Observations from the great flashcard challenge of learning Japanese.
One is that my progress gets slower and slower. This is due to the fact that as I learn more cards, I have to spend more time reviewing and less time learning new cards. Occasionally a couple hundred cards will expire over the course of a few days, so I have to slog through the review stack before I go on to new cards (by personal choice, not a software limitation).
Second (and more interesting) is that flashcards don’t automatically go both ways. Just because I can read a character or a word doesn’t mean I can write that same character or word. Instead I have to have a separate stack of cards that’s reversed. Based on this it seems like memory links in the brain go only one-way. Except that it’s not perfectly so—it’s much easier to learn a card in reverse if I’ve already studied it forwards.
Third is that while a mnemonic is helpful when first learning a character, after several reviews it becomes useless. From that point on the associative link in my mind is so strong that I know the meaning and reading without having to think. I’ve learned now to trust the first thing that enters my head when I see a character—it’s rarely incorrect, and if I’ve really forgotten a character I’ll often just draw a blank instead of an incorrect answer. More often than not I’m surprised by how effortless it is to remember things 1,100 characters into my list of 2,000.