My first encounter with Supermemo was three and a half years ago. In an effort to remember Japanese vocabulary, I created many paper flashcards. The bigger these stacks of paper became, the more cumbersome it was to review them at regular intervals (I had different stacks that were reviewed on different days, all marked on a calender). Despite my efforts, over time I realized that my retention was generally low, and this was quite discouraging.
"Maybe software has already been written to handle this task of rescheduling flashcards," I thought. After a somewhat thorough search, I narrowed my search to two choices: StackZ and Supermemo. Although the Supermemo web site was somewhat hard to understand (It isn't very pleasing to the eye), the reasoning was sound. But StackZ (http://www.stackz.com/index.html) had more instant appeal than Supermemo (At least to me), so I tried it first. Initially it seemed to satisfy my needs, but in the end I encountered the same problem: There was no "master stack" where all of my flashcards resided, they all remained in their "mini-stacks." In other words, if I wanted to review my daily flashcards, I would have to go to each stack of cards and review the allocated "outstanding" cards. If I had 200 small "stacks" of flashcards (Which would be a reasonable amount, theoretically), and each stack had only one card to review, I would have to check each of the 200 stacks and review the single flashcard. Could the computer not do this for me? After I realized this (And a few other things) I stopped using StackZ.
After this I began to use Supermemo. Two conclusions I figured out while reading about Supermemo's methodology were: (1) 'As long as you review all of your daily allocated cards, you can add as much material as you wish.' and (2) 'Because Supermemo's spacing algorithm is always trying to find the limitations of your memory (The furthest interval it could be without forgetting it), when it comes to learning vocabulary, SuperMemo appears to be the most efficient method that exists right now.'
Although such a conclusion seemed too good to be true, since I could not disprove the logic, I began using Supermemo every day.
Two weeks later, I effortlessly recall the word "doorbell" ( 呼び鈴). Even though I never used this word (Other than when making the flashcard), I had no trouble recalling it. Why was this? "Ah, I put this word in Supermemo," I thought to myself. I began adding even more words to Supermemo, almost all of which could be recalled with minimal effort.
"This is it. This is what I've been searching for," I thought.