The Forgetting Curve:
Why you forget (and how to stop it)
Within 24 hours, you'll forget up to 70% of what you learned today—unless you do something about it.
What is the Forgetting Curve?
The forgetting curve was discovered by German psychologist Hermann Ebbinghaus in 1885. Through rigorous self-experimentation, he mapped exactly how memory decays over time.
His finding: memory decay follows a predictable exponential pattern. Most forgetting happens within the first few hours, then gradually slows down.
The good news? Strategic review at the right times can flatten this curve almost entirely.
How Memory Fades
Without review, here's what happens to your memories:
After 1 month, only ~20% remains. But each strategic review resets the curve.
How to Combat the Forgetting Curve
Strategic review at the right times changes everything
Immediate Review
Review within 24 hours of learning. This catches memories before they fade significantly.
Spaced Repetition
Space out reviews over increasing intervals. Each review resets the curve.
Active Retrieval
Don't just re-read—quiz yourself. Active recall strengthens memories more than passive review.
Interleaving
Mix up topics during review. Harder in the moment, but creates more durable memories.
How Cruxly Fights the Forgetting Curve
Knowing about the forgetting curve is one thing. Actually reviewing at the right times is another.
Cruxly's spaced repetition algorithm does the scheduling for you.It tracks what you know, predicts when you'll forget, and prompts reviews at optimal intervals.
You don't have to think about when to review—just open the app and study what it tells you to. The algorithm handles the science.
FAQ
Is the forgetting curve the same for everyone?
The general pattern is universal, but the rate varies. Factors include how well you learned initially, emotional connection to the material, sleep quality, and prior knowledge in the subject.
Can I ever completely stop forgetting?
For practical purposes, yes. After enough spaced reviews, information can stay accessible for years. Truly 'never' forgetting isn't realistic, but near-permanent retention is achievable.
Why do we forget so quickly?
Forgetting is actually useful—it clears out irrelevant information. The problem is that your brain doesn't know what's important. Strategic review signals that something matters and should be retained.
How does sleep affect the forgetting curve?
Sleep is crucial for memory consolidation. Poor sleep accelerates forgetting. Studying before sleep and getting adequate rest can significantly slow the curve.