The Forgetting Curve: Why You Forget and What to Do About It

Within 24 hours of learning something new, you forget about 70% of it. Within a week, almost all of it is gone. This isn't a personal failing — it's the forgetting curve, discovered by Hermann Ebbinghaus in 1885, and it applies to everyone. Your brain is designed to discard information it doesn't use again soon.

The good news: each time you review material at the right moment — just as you're about to forget it — the curve flattens. After four or five well-timed reviews, the information moves into long-term memory. The key is reviewing before you've completely forgotten, not after. This is why cramming fails and spaced review works. Your brain doesn't keep what it doesn't revisit.