As SuperMemo makes learning easy, you may be tempted to learn much more than you really need. Only in time will you discover the true extent of knowledge that pertains to your interest and the fact that although SuperMemo is extremely effective, it is not omnipotent and, in limited time, allows you to master only a limited amount of knowledge. Working immoderately, sooner or later, you will be overwhelmed by the amount of repetitions, and will discover the true capacity of SuperMemo (throughput), which is proportional to the daily allotment of time.
Working with SuperMemo imposes a strict limitation on the amount of new knowledge that can be learnt in unit time, and requires particularly accurate selection of material. In choosing facts and rules to remember, you should primarily use the criterion of applicability. A multitude of items may seem worth knowing, but because of the limited capacity of memory, only a small fraction of them may be mastered, and the choice should favor items of the highest applicability in day-to-day situations. You will not waste much time if you include items that you would remember anyway just because of their high daily applicability. Therefore, you better always err on the safe side, and include all important items you are not sure you would remember. Concerning the selection of the material to learn, another general principle is that you should first master the most fundamental aspects of the learned subject and get into details at later stages of work. Meticulous dismembering of textbooks page by page is bound to produce excess of details at the cost of principal knowledge. An important psychological aspect of the general-to-specialized approach is that you can soon discover great profits coming from the perfect knowledge of the most fundamental facts in your field and become yet more encouraged to expand your knowledge system into more detailed areas. With amazement, you will notice how new facts and rules slot in in what you have already learned.
Good foundations make it easier to slot in new knowledge structures, provide additional encouragement to work, and free you from the unhealthy impression that you are acquiring knowledge for the knowledge's sake.