Gyaata
The forgetting check
Pick a subject, tell us roughly when you last revised it, and answer five questions. No account, no email, and no result held back until you sign up. What you get at the end is a count of how many of those five you recalled — not a percentage, not a retention score, and not a verdict on your memory, because five questions cannot support one.
The research, not you
Hermann Ebbinghaus published the first map of forgetting in 1885, from experiments he ran on himself using invented nonsense syllables. What he measured was not recall but savings in relearning: he learned a list, waited, learned it again, and recorded how much less time the second pass took. Murre and Dros reproduced the curve by the same method in 2015.
So the shape is real, and it is the reason revision timing matters more than revision volume: forgetting is steepest right after you learn something and flattens out afterwards. What does not survive the trip is the numbers. A figure derived from one man relearning meaningless syllables is not a measurement of how much of a chapter you have lost by Sunday — which is why there is no such figure anywhere on this page.
The check above asks five specific questions from one deck. Whatever you scored is a fact about those five questions and nothing else. We do not know what you have studied, when, or how well — the only thing on that page we know about your timing is the sentence you told us yourself, which is why it is quoted back to you rather than asserted.
Sources
Ebbinghaus, H. (1885). Über das Gedächtnis: Untersuchungen zur experimentellen Psychologie.
One participant — Ebbinghaus himself — memorising invented nonsense syllables. The measure was savings in relearning, not recall.
Murre, J. M. J., & Dros, J. (2015). Replication and Analysis of Ebbinghaus’ Forgetting Curve. PLoS ONE 10(7): e0120644.
A successful replication by the same method, again with a single subject. The shape holds up; the percentages people quote off it were never about anybody else.
That is the complete list, because those are the only two claims on this page that need one.