Canonical · Mental Models · Infographic
The Feynman Technique and the Leitner System
Josh Sanders (compiling Feynman and Leitner) · 2026
"Genuine understanding is tested by whether you can explain a concept simply enough for a child, and genuine retention is engineered by spacing review intervals according to how well you already know the material — two separate mechanisms that most study habits conflate into one vague 'studying' activity."
If you can't explain it simply, you don't understand it yet. That's the entire Feynman Technique in one sentence.
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Up NextSuggested: Continues the theme of Mental Models
The Feynman Technique: The Ultimate Guide to Learning Anything Faster
"You don't actually understand something until you can explain it in plain language a 12-year-old could follow — complexity and jargon are usually masking a gap in your own understanding, not evidence of sophistication."
Farnam Street (Shane Parrish), after Richard Feynman · EssayContinue→