The Decade of SuperMemo:
Interview with people who brought SuperMemo to life
Compiled by M. Morawska
Summer 2001 (updated Fall 2002)
Editorial notes placed in square brackets.
On July 5, 2001, SuperMemo World celebrated its 10th anniversary. On that occasion we wanted to look back at the the past decade and see how the coming decade could capitalize on the accumulated experience. The questions for this interview were all identical and were sent via e-mail to all people who played a role in bringing SuperMemo to existence. Not all interviewees met the deadline of three months set for completing this review. Some questions were ignored. Some answers strayed from the subject. Nevertheless, the outcome of this compilation should serve as a rich material for those interested in the world of SuperMemo and its history, as well as those who are interested in the hard life of companies trying to sell software in and from Eastern Europe.

Interview participants: Wozniak (Dr Piotr Wozniak, author of SuperMemo), Murakowski (Dr Janusz Murakowski, co-founder of SuperMemo World and contributor to the SuperMemo method), Gorzelanczyk (Dr Jacek Gorzelanczyk, contributor to the SuperMemo method, author of numerous publications in the area of memory and learning), Biedalak (Krzysztof Biedalak, Msc, co-founder of SuperMemo World, CEO, primary creative force behind most commercial products based on SuperMemo), Georgiew (Marczello Georgiew, Msc, co-founder, long-time marketing director at SuperMemo World), Hejwosz (Michal Hejwosz, founder of SuperMemo Library, author, contributor to software design, student of economics), Sebastian (Sebastian Wesolowski, MSc, programmer, creator of SuperMemo 1.0 for Windows CE and chief programmer of on-line SuperMemo), Wojcieszek (Krzysztof Wojcieszek, MSc, programmer, father of SuperMemo for Amiga, developer of SuperMemo 2.0 for Pocket PC), Bajer (Petr Bajer, MSc, father of SuperMemo for Palm Pilot), Mols (Maarten Mols, MSc, father of SuperMemo Nederlands


If SuperMemo works as advertised, why isnít it as popular as an Internet browser?

Biedalak: Isn't it like you asked "why drinking coffee is more popular than regular exercise?"

Gorzelanczyk: It is the problem of motivation. Few people really enjoy learning. To use SuperMemo, learning must be like your hobby

Bajer: An internet browser doesn't ask you to do your repetitions every day. All SuperMemo does is make your learning more effective. Based on their school experience, most people just don't like learning, no matter how effective it is. They would rather use a tool that would do the learning for them. Such tool won't be developed soon, so only those who are able to work hard will be rewarded with results in learning.

Hejwosz: I would pinpoint the following reasons here: 

  1. It is not the software for everyone; it requires lots of self-discipline before it comes to reap the harvest and I am afraid many people are rather driven by the instant gratification, 
  2. I do not think people get convinced about the real power of SuperMemo; there are quite a few examples of spectacular success with SuperMemo, but there are many more people who succeeded without it
  3. SuperMemo has lots to do in terms of simplicity and user-friendliness

Sebastian: People generally do not trust revolutionary technologies. They are flooded daily with not-so-honest advertising. Many times an advert will promise you the best things in the world, and when you buy the product, it turns out to be a big disappointment. Besides, laziness is part of human nature.

Wozniak: When setting up SuperMemo World, we thought SuperMemo was a product that would spread like wildfire. This came from little understanding of the differences in psychological profile of people that make up the studying population. It was an erroneous extrapolation from our own perception of SuperMemo to the entire population. It is true that people who are very smart often grasp the concept in minutes and then become awfully enthusiastic. However, they are a tiny minority. Enthusiasts from around the world come to me with various marketing ideas, ready to form partnerships or conquer foreign markets, and I invariably have to begin with "Cool down!". SuperMemo is far harder to sell than it seems at first. We need to realize that people are different and their approach to SuperMemo differs. Inherently, SuperMemo is not viral. To understand its limitations we need to dig into psychology, sociology and mathematics. In memetic science, there is a research field some mathamaticians call "social percolation theory". It describes networks of individuals, their communication means, the spread of information in such networks, and the variables that affect it. Let me use some concepts of that theory to explain my point. SuperMemo does not have the Whoa factor that makes an Internet browser spread. It is therefore inherently aviral, i.e. it does not percolate. It's smoothness factor is low. I heard many voices that if SuperMemo were simpler or if it had a better user interface or if it was translated to Polish or French, or if it came with a plain language documentation its ability to percolate would change. Simplicity will not take away SuperMemo's inherent problem with smoothness. Nobody can sit to SuperMemo and feel the enlightenment or joy of playing with the browser. That is the key! Several variables in a social percolation model stand against SuperMemo. Many top-IQ people and great programmers were given the idea of SuperMemo to their free hands to capitalize on the previous experience. They tried to develop a better wrapper for the idea. A better "viral capsule". In other words "better SuperMemo". I intentionally stay away from similar efforts to make sure I do not pollute their creativity with my own preconceived molds. Those smart people could never come up with widely viral product they hoped for. This is not their fault, the fault is inherent in the concept. Our brain does not have a reward-punishment system for measuring memory or forgetting. Ignorance is rather painless, and knowledge SuperMemo helps you keep in your brain is always taken for granted. Knowledge "feels" as if it was to stay in your brain anyway. It is the "feeling" that matters. It is very hard to build impressive and massive bodies of knowledge because persistence and will power stand on the way for a majority of people. Only when you learn a huge body of material you develop the skills, the awareness, and the deep understanding of what SuperMemo does to your life. Only a very small proportion of people really "feel" SuperMemo and its power. But this "feel" and awareness often takes years. That disqualifies SuperMemo as a viral product. Not only it is not smooth. Its velocity is deplorable. It does not ride on the first experience and instant gratification, it rides on hard-earned wisdom. Those weaknesses are inescapable and will always be there. Naturally, there were cases where a small niche of users was quickly saturated, where SuperMemo conquered a whole class in a school or university, but these cases were always based on individual leadership. Where one or very few very smart people got infected with the idea and were able to make others follow. However, those niches collapse as soon as leaders are gone! SuperMemo keeps on spreading among people for who knowledge is the matter of survival or who simply love learning. Those people begin their adventure with SuperMemo by understanding the core premise: there is no efficient learning without spaced repetition. Today (2001), this translates to: there is no efficient learning without SuperMemo. Without this core conviction, people are not able to persist with SuperMemo, let alone drag others into the circle.

Georgiew: Unfortunately, practice shows that for many, SuperMemo does not work as advertised. This is all related to human psychology. I am sure that computer applications will not replace standard methods of learning for a long time to come. Most people do need motivation for learning and computer is not able to generate this motivation. With SuperMemo, you can learn whenever you want, and whatever you want. However, most students need a rigid schedule to stick to. Only schools and universities force you to follow their curriculum. Both the carrot and the stick. Most people need an authority within the learning system. This simplifies life as for questions such as: Why do I need to learn this and not that? Is this theory true? etc. Furthermore, people like to learn in a group, having contact with others, competing with them, working together, etc. Typically, users regard the computer as a "dummy machine" and subconsciously reject its authority. Without self-discipline, SuperMemo is useless

Are you satisfied with the progress of SuperMemo? Did it meet your expectations?

Wozniak: Yes and no. In 1991, we expected SuperMemo to take the world by storm. We expected piracy to be our main headache. This did not materialize. In that respect you will probably hear unanimous "No. I am not satisfied". However, SuperMemo exceeded my expectations in its ability to grow with new ideas. For example, I did not predict the power of incremental reading and how SuperMemo would be able to inter-link learning with the World Wide Web. Today its power is by far greater than what I expected possible ten years ago. Because I am rather immersed in research, development and learning (as opposed to marketing), I am very happy with the present status quo. I leave the commercial headaches to my colleagues and partners. Overall then, I would say, SuperMemo exceeded my expectations. But then ... I am an inveterate and incurable optimist. I think what you hear from Biedalak or Georgiew will be a better reflection of reality :)

Bajer: Yes, I am. SuperMemo did meet my expectations because I wrote the PalmOS version myself to meet my own expectations :-)

Biedalak: No. But things get better. Is it cause I'm getting older? :)

Murakowski: No. SuperMemo has been a great idea from the start. Its implementation under DOS environment, while crude and rudimentary by today's standards, was relatively functional and easy to use. However, its Windows implementation always failed to live up to expectations. Beginning with first versions, which offered nothing but the DOS functionality in Windows. Subsequent versions required the user to jump through the hoops to get what they wanted [Murakowski is in minority today - he does not use SuperMemo himself]. The current version [SuperMemo 2000] is not much different in this respect. It is almost as if we strived to hide features from the user by using nonstandard keyboard shortcuts and nonstandard GUI.

The problem with SuperMemo is that it claims to save the user time, but it fails to live up to this claim. Here is why. In order to realize this time saving, the knowledge has to be in the form of a SuperMemo collection. So, how do we get it there? One way is for the user to put the knowledge in this form. This takes time. While it is not as big a problem for elements of pure text (at least for people sufficiently skilled in keyboarding) it is an almost insurmountable obstacle if some graphics/math/sound is desired. The user interface is terribly unfriendly. What in other applications takes seconds, requires hours of digging through documentation in the case of SuperMemo. Moreover, if you want to have some structure in your collection, so that your survival English is not mixed up with high energy physics or algebraic topology... use pencil and paper version of SuperMemo for better use of time.

Another way to have the knowledge in the form of a SuperMemo collection is to have it commercially available. The problem here is that there is not enough variety, so it is usually not possible to find a quality collection on a subject of interest. The reason is that apparently there are not enough authors interested in preparing quality collections. Why is that? Again, it is the user interface barrier discouraging potential authors.

Georgiew: No. I wanted to boss a 50 times bigger entity. SuperMemo for Windows went too far into advanced techniques that make it too complex to an average user. I am very happy with the Internet version and its development though. It is the most user-friendly and usable soft we have ever created. From the very beginning, it is 100% user-oriented. That is the key to its present success. I want to place it on big Polish portals, make it an Internet learning standard. Make it pay for itself at some point. I know that our competition regards this market section as unprofitable and they might be right. However, those who come first will win the field. And then ... the winner takes all! We can dominate this important niche soon. I want SuperMemo to become the Internet-based learning standard. Perhaps then I will finally say I am satisfied with the progress.

Sebastian: More or less. But I'm working on it. My new on-line version will be the best :)

Hejwosz: Yes, SuperMemo did and still does meet my expectations. Moreover, it oftentimes blazed the trails in the directions I had never expected it. As for the progress of SuperMemo Library, no. I am sure I will never be fully satisfied. It could always be better. However, my "dissatisfaction" is rather a positive stimulus for harder work. It is not a destructive power. No matter where we are now, there are far brighter prospects for the future.

Mols: Concerning the progress of learning with SuperMemo: yes! It's fabulous. It has brought much more than I expected when I first discovered it in 1996. As for the development of new upgrades: user-friendliness has increased, but a lot of things are still very complex for new users

What was the most important moment of the last decade?

Wozniak: The string of awards for SuperMemo in 1992 that helped us start off with the business, major increase in sales with the introduction of CD-ROMs in 1994, establishing in 1997, SuperMemo Library in 1998, incremental reading in 2000, and support for HTML soon [see: SuperMemo 2002]. If I was to choose one, it would be incremental reading. By far.

Hejwosz: I cannot speak much about the last decade as I am in SuperMemo business since 1997. Since then, I think it is the establishment of SuperMemo Library in March 1998. For the first time, users have an easy access to a wide range of learning material for SuperMemo. At least those who speak English

Georgiew: Developing

Bajer: I have only been with SuperMemo for 3 years so I cannot speak for the full decade. For me it was the move to the handheld computing. This allowed people to save time not only by optimal repetition spacing but also by filling the moments of the day that would otherwise be wasted.

Gorzelanczyk: Publishing the article on the two variables of memory, and major progress in modeling the glutamatergic synapse.

Mols: My own discovery of SuperMemo (after having programmed something similar in the late 80's end early 90's). Secondly: my decision to start SuperMemo Nederland. As for SuperMemo itself, it seems it was very important to make SuperMemo a Windows-application [originally SuperMemo was a DOS program]

Biedalak: When I first wind-surfed hanging on a ballast belt [explanation: a ballast belt is a belt binding the surfer's waist to the boom to help keep the sail in an upright position while gliding in strong wind]. Seriously ... I liked Fall 1994 when Advanced English was selling like hot cakes

What is the most important thing for SuperMemo to become more popular?

Bajer: Help people realize that wisdom and learning really pay.

Sebastian: Simplicity! People must be able to use SuperMemo without ever reading documentation.

Biedalak: SuperMemo must be as intuitive as possible. There is also a problem of user motivation. We need to better understand it and target this area by identifying and addressing existing needs for effective education rather than trying to create them in too broad, i.e. population-wide, environment

Georgiew: It must be easy to use, include the most important options only, be user friendly, provide lots of content, and provide as much free stuff as possible (esp. over the Internet). The other component is beyond our influence: the awareness of the need to invest in training. This awareness is developing ok in the west, but in Poland, for example, only 3% of company's budget might go into training and 20% of that is computer-based training. With time, I am sure though, an attractive niche will develop. 

Wozniak: It must improve its smoothness and velocity (see my earlier answers for an explanation). For that it must be as simple as possible, and it must be wrapped in a message that is easy to communicate. will be central in further research in that area (i.e. spreading the message, user feedback, etc.). I have no illusions though: this process will be painfully slow and will take many years.

Murakowski: Make it easy to use! Without sacrificing functionality. Make it as easy as a word processor, or a presentation editor (MS Word, MS PowerPoint). Make it easy, and they will come. Use standard keyboard shortcuts. Use the user interface of the most popular software available on the market. Look to the Microsoft productivity tools (the MS Office suite) for guidance.

Wojcieszek: Work, work, work. Pocket PC version has lots of unfulfilled potential due to my involvement in many projects at once.

Gorzelanczyk: SuperMemo must be easy to use. It should come with ready-made learning material for specific purpose. I found that my students were most successful when they had a clear goal (e.g. exams for medical college) and a material that gave them the promise of solid knowledge (e.g. Biology for Medical Candidates). Last but not least, SuperMemo needs money and publicity.

Hejwosz: I think SuperMemo should be user-friendlier. There should be more learning material for the program too.

Mols: Further increase user-friendliness and delete too complex and rarely used features.

What was the biggest mistake of the authors of SuperMemo?

Biedalak: I would turn things upside down if I had a second chance. Well ... there were many mistakes. Starting from early geographical setting and product shaping. I believe we would do better having started in the US. I think it would be no fun to start it in Poland again. If I am to "fantasize" about what could have given us more chances for success, I would say we should try our strengths on the biggest, most dynamic (and most competitive) market right from the start. As for the product shape, I agree Piotr is a vital driving force behind SuperMemo innovation, but we certainly should have pushed harder for shaping the product in a way that meets the market needs. I would make the product more market-oriented. But this is a very long story.

Georgiew: We failed to saturate the Polish niche and let the multimedia competition fill the gaps. With complex software and miserable support for our own Polish language, the competition ate most of our cake. We could have used it to catapult to western markets at an earlier stage. We set the priorities wrong, and squandered the excellent beginning on the Polish market.

Bajer: The name SuperMemo. Not only does it not express what the product does but it is misleading as well.

Sebastian: Lack of collection exchange standard. Hopefully, the new XML data definition will fill in this gap

Wojcieszek: Perhaps no coordination in the beginning while designing Windows, Pocket PC and Palm Pilot versions? Many users use both a PC version and handheld version.

Murakowski: Never employing an expert on user-friendliness of SuperMemo's interface. Having only one person decide on the direction of software and its development. While team effort has always been bogged down by miscommunication, it is necessary for many people to look over each other's shoulders to root out quirks bound to appear in the program.

Gorzelanczyk: I do not know. I am not the best person to ask. It would better be discussed with Piotr

Wozniak: Wise men say that only fools cannot find errors in their conduct. However, I see the last decade as strongly deterministic. Even with today's knowledge it would be hard to change much in the course of action. I am not kidding here! I always spend lots of time analyzing the past and it all seems to have gone the way it had to. Interestingly, I read that people with high serotonin are far more likely to see things that way. I may be slower to learn from my own mistakes but ... at least I will live longer [Simon Woodroffe claims that people of success are generally bad at spotting their own weaknesses or past mistakes]

Mols: Adding more and more new options to earlier versions. The program has too many options and for 95% of the users it has become too complex. I think I understand 80-90% of the options, but it cost me a lot of study. Of course when using ready-made content you can lock the collection in Learn-Only mode and Basic level. But a lot of people like to make their own collections. Very soon they get lost in the maze of options, buttons, menus and SuperMemo-glossary

What is the greatest success of SuperMemo?

Bajer: SuperMemo saves many people time and helps them achieve their goals.

Georgiew: Software for Europe award and a string of appearances at CeBIT.

Gorzelanczyk: The effective learning method. Getting quick popularity in Poland in 1992-1994.

Murakowski: Going Internet. But then, again, it was an obvious thing to do. 

Wozniak: Being an amazing learning tool, and still being able to improve learning efficiency from year to year.

Mols: The fabulous algorithm.

Do you use SuperMemo? In what subjects?

Gorzelanczyk: Yes. English, internal medicine, and materials related to students education (e.g. biology)

Biedalak: Yes. I used SuperMemo intensively for learning business when I studied it academically. Now I mostly brush up my old English collections. I invested too much in my GRE vocabulary knowledge to let it go

Bajer: Yes. I sure do. That's why I wrote the PalmOS version in the first place: to be able to use it myself. I use it for learning English and for just about anything I consider important to keep in my mind.

Hejwosz: Yes, I do. Subjects such as: economics, computer science, mathematics, physics, geography, sociology, social psychology, psychology, history, English, German, etc.

Mols: Yes. 20-25 minutes. 150-200 items per day. I have around 25,000 elements memorized (mostly items). Subjects: English (incl. Advanced English), French, Spanish, Topography, Computer Science, Neuropsychology, Economy, and a personal general collection with all kinds of information I like to remember

Georgiew: No. I approached it over 20 times and always failed to make regular repetitions. Today, as I am studying for an MBA at the University of Economics in Poznan, I started yet another collection to brush up on economics. I have failed again though. Why? I really prefer to go to the university and learn there with my group. Working with a PC at home alone just isn't my way. Well ... with the new Advanced English 2002, I hope to make some real good progress in English vocabulary soon :)

Sebastian: Yes. Learning English from time to time.

Murakowski: No. I liked the DOS version. Windows version irritates me. Life is too busy for struggling with non-standard GUI.

Wozniak: Yes! You won't find a more obsessive user! SuperMemo was born from my compulsive need to remember things. I memorize everything I got time for. I memorize the gym hours because I do not want to hit the locked door (which would cost me more than those few seconds I need for repetition). I memorize all family birth-dates, occupations, stories and connections because I never want anyone to think I failed to remember his or her story. I cram all sorts of knowledge because ... it does not befit an educated man to slip on Roman history or geography of South-East Asia (i.e. the stuff taught in the primary school that most adults have problems with). Most of all though, I learn for a very specific purpose of understanding the brain, memory, learning, the role of sleep, emotion, nutrition, etc. This is my job. I need to understand implications of SuperMemo on many platforms so ... I keep on learning. I take a break only for 7-10 days each year during the summer vacation when I stay away from the computer and try to get a higher-level perspective on life 

How do you see the future of SuperMemo and learning in general?

Bajer: Most of the time people spend at school is unproductive and boring. Improved school system combined with SuperMemo could significantly shorten the time people spend on learning, and this could also change people's attitude to learning. People would no longer see learning as pain and waste of time, which would have positive influence on our lives. However, this will take a very long time to achieve.

Mols: It is very important to promote the concept of life-long-learning. The problem is with convincing people to change their attitude towards learning. Most people seem to accept the process of forgetting. They consider it unavoidable, and they don't seem to be troubled by it. They consider daily learning with SuperMemo too much of a burden.

Gorzelanczyk: I can only speak of what I believe is most important for the science behind SuperMemo. Constant improving of the algorithm is an obvious point. However, there should be more attention paid to the concept of two variables of memory. There is a huge potential for new scientific discoveries in the area of molecular biology of memory if this concept is better understood by researchers in the field. I plan to focus on modeling adrenergic and glutamatergic synapses. I was able to attract new talent to my institute and hope to see major progress soon. I would like to take a holistic approach to the glutamate synapse and supervise a solid PhD in this area. New models should take into account alternative splicing of the NMDA receptor. I will also look for new inspiration in areas of schizophrenia, language, and semantic memory. With Dr Wozniak, I would also like to look for correlates between various psychological tests and the SuperMemo learning process. 

Georgiew: We will focus on Internet-based learning will become a standard. We will enter schools where server-based data is a blessing; now any kid at school can delete the learning material from the hard disk! Then we will enter to the B2B market and finally recoup our Internet investment. We will develop more and more content that is particularly suitable for SuperMemo (such as languages, school material, professional training, etc.). We will provide for close integration of all SuperMemos, which now develop without insufficient coordination. The sky is the limit. Ultimately, we will set new standards that will force Microsoft to take training more seriously :)  

Murakowski: Not good. In the decade, fortunes have been made and squandered. Wars fought and lost or won. Software tools have risen to prominence and sent to virtual oblivion. SuperMemo has only been struggling, trying to keep the head above the water. It's been a software zombie, kept alive (on life support, should I say) by admirable efforts of a single man.

Wozniak: Future of SuperMemo is bright! It is hard to predict where it will go, but if the next decade is half as good as the past one ... I already die to see the outcome. As for the business side, the Internet will make the software market approach the perfect competition model. In other words, it will never be a bonanza. Profits will be hard to earn, meager and proportional to the power of innovation. All that on condition we are able to wrap innovation in a user-friendly package. 

If you were to jump into SuperMemo again, would you do it or would you choose another career?

Wojcieszek: Yes. Absolutely!

Biedalak: Because of the early vital impact on my personality and knowledge, I would surely stay close to SuperMemo.

Hejwosz: I would certainly choose SuperMemo again. 

Gorzelanczyk: Learning,  memory, nervous systems and computers ... I cannot see anything more fascinating in the world.

Bajer: No hesitation. I would do it again. I like the job.

Georgiew: We entered the worst field for doing business. This area is full of dynamic high-IQ people. It is full of top-quality professionals. It is also rich in investors ready to splash a fortune in order to catch their chance. It is a do or die area. Not a very nice place to be. When we missed the train the first time, we could have looked for a quieter place for doing business. Our profitability has been a disaster most of the time. I would choose this field only for personal fulfillment and growth; however, I would certainly enjoy more freedom and profit elsewhere.

Sebastian: I would choose SuperMemo. It has a potential and there is still lots of work for me to do.

Mols: I would do it again

Wozniak: The world is deterministic. I believe that set in the same position back in time I would do exactly the same thing again and again. My personality drove me to organizing my learning process. It had to end up in doing SuperMemo. It had to end up on the Internet. So many new vistas open today. This must be the most exciting moment of all time. However, if I knew how much blood, sweat and tears the decade would take, I would certainly be surprised. Never mind. The laws of thermodynamics say that life is not supposed to be easy. I love my work.

What is the main lesson you have learned?


  1. Control all paths crucial for building a consistent vision
  2. Learn broadly, concentrate operationally
  3. Spread competence but count on yourself

Hejwosz: I do not think there is a lesson I would point to as the most important. My whole over 3-year long experience with SuperMemo Library has made me a very different man in comparison to whom I was at the beginning of the road. I have learnt a zillion things; probably too many to ever consider listing them here.

Georgiew: I have spent with Krzysztof [Biedalak] more time than with my wife! We can quarrel, we can be angry with each other, but I know I can always rely on him. Although I wouldn't marry him I could run any business with this guy! :)

Bajer: People are extremely different.

Mols: (1) That I am the director of my own memory. Forget about forgetting. If I want to remember something, I know how to do so. And I do remember most of it. 
(2) It's hard to make money on SuperMemo. You really need to put lots of hours.

Wozniak: I like this question! Awfully hard and awfully important! There are many simple maxims we should have learned at school, but only hard lessons of life hammer it to our awareness. This is my pick:

Last word: Bottom of the mail comments

Wozniak: Sorry for didactic tone and lengthy answers. Some questions are very important and require scrupulous analysis. With impatience I wait to see the final outcome of this interview project. "We, the guys who spread SuperMemo" [quote from SuperMemo "anthem"] also differ like chalk from cheese :)

Biedalak: Sorry for my short responses. The questions are exactly of the kind that require quite a bit of thinking and "creative" prose. But ... you know ... business is busy :)

Wojcieszek: I am very busy right now. Perhaps some other time I will send some more complete answers.

Murakowski: I am not sure my blasting criticism and stark sincerity are good for business and publishable. Please skip whatever you consider inappropriate for "public view" [all responses where quoted entirely with minimum editorial intervention]

Georgiew: I still hope our dreams are to come true. For that we need to stick together with a coherent vision of the future.

Bajer: Many revolutionary theories and inventions were not widely accepted in the beginning. Fads that spread like wildfire usually do not last long. The fact that SuperMemo fits the first category is promising.