Why you forget most of it in days: Ebbinghaus's forgetting curve
30seconds
In the 1880s Hermann Ebbinghaus learned lists of nonsense syllables, tested himself after delays from 20 minutes to 31 days, and drew the first forgetting curve: a steep early drop, then a long tail.
Play with a simple model of that curve. Tap the chart to schedule reviews and watch each one reset the memory and slow the next fall. Four reviews crammed into one day barely help; the same four spread over two weeks leave far more at day 30. It's the idea behind spaced-repetition apps, and you can feel it in 30 seconds.
Deep dive · 4 min
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