The other day it occurred to me that I’ve been using SRS my whole life to learn language. Chances are, you have too.
Think for a moment about what the average kid newly fascinated by books does, without ever having heard of Anki. Show her a new book and it is immediately devoured, with frequent questions being asked of the parents. But it doesn’t end at the one reading; the book is read over and over and over, several times a day perhaps, then less often as other books show up, then whenever she remembers it, until the time comes that she has outgrown it entirely. This process continues (for the more bookish sort of kid like myself) well into the teen years – I probably read Treasure Island a dozen times, for example. And the last few times I read it were further and further apart. I would suggest that this is a typical, normal pattern; and is the mind’s way of instinctively reinforcing what it has learned. While there might not be a conscious moment of thinking “ah, this memory is getting fuzzy, better reread”, I believe that this is actually what is going on subconsciously; although, if you asked the child in question why she hadn’t read such a book lately, she’d just say she was “tired of it”. At that point, the reinforcement that comes from randomly seeing the words in the immersive native-language environment is good enough to keep the memory alive.
Using an SRS program can sometimes give the illusion that a memory has a defined point, precisely calculated by the computer, where the fact is deleted from the drive. Of course, that isn’t actually the case; rather, they get a little fuzzier every day until at last they can’t be recalled at all. Since the precise date of being reminded isn’t nearly as critical as the program suggests, it might well be that this sort of instinctive SRS is just as efficient as the more regulated and high-tech variety.
Adults, you might think, don’t tend to come back to books or other media again and again, and therefore it might not work too well to depend on this sort of instinct. That may well be true mostly, but there’s one area where nearly everyone follows this pattern throughout their lives, and that is music. So here’s your homework (and mine): take the newest Japanese songs that are in heavy rotation on your playlist, get the lyrics (maybe from jpopasia or goo), and make sure you understand them fully. This isn’t extensive reading where you can skip over things; you’d want to get every word down. Then, just listen to music as you normally do, no need to enter the whole song into Anki. I suspect that a few months down the road, when you think of listening to that album again after it’s been collecting dust for a while, you’ll still remember everything you learned.