The point of spaced repetition is to have you recall something right when you're just about to forget it. If you recall after it's been forgotten, that means you're forgetting a lot more, which means the system isn't working.
You should be forgetting a lot in your life and learn a lot. Remembering is overrated. Learning the same thing second or third time gives you better understanding.
1. As others have said, the idea is to study something before you forget.
2. It's hard to predict when you're going to forget something, so you do wind up studying a bunch of stuff before you really have to. It's a limitation of prediction (and also of the technology as developed so far).
3. It really is pleasant to work to recall things even when you succeed at it. It does "freshen them up" in your memory. And sometimes just the experience of seeing a fact can be pleasant. (A lot of us review familiar things for the joy of it in other domains--movies, etc.)
I guess I can see how someone might be enjoying this. Especially folks who are into excercise of any kind. But it's not for me. I think there's value in forgetting and re-learning as needed.
I learned A* at least 5 times already. And each time I learn it, I feel like I'm having better appreciation and understanding of how it works. Each time I'm falling in different traps, make different mistakes, that teach me more. I wouldn't have that insight if I just memorized how to correctly implement it the first time and recalled it whenever I needed a new implementation. Also I'm perfectly happy not knowing how to implement A* in between times that I need it.
I would like to be reminded that things exist, after I forgot them, so 20% sounds way more fun for me.
Anyways, thanks for sharing your fun. Don't let me be a buzzkill. ;-)
That sounds nearly perfect for FSRS [1], the default spaced repetition algorithm used by Anki, which aims at estimating the time it takes for memory stability to decline from 100% to 90%. At the estimated 90% stability point, FSRS would require a review, so naturally a mature deck of flashcards would hover between 90-100% stability.