The Feynman Technique: The Best Way to Learn Anything

https://getpocket.com/explore/item/the-feynman-technique-the-best-way-to-learn-anything
You don't know anything until you can explain it.

Learning From the Feynman Technique

https://medium.com/taking-note/learning-from-the-feynman-technique-5373014ad230
How to learn stuff from one of the heroes of modern physics: Richard Feynman.