Кривая забывания информации в мозгу
https://upload.wikimedia.or.../ForgettingCurve.svg

In 1885, Hermann Ebbinghaus extrapolated the hypothesis of the exponential nature of forgetting. The following formula can roughly describe it:

R=e^{-\frac{t}{S}}

where R is memory retention, S is the relative strength of memory, and t is time.