Online explanations of the Feynman Learning Method are largely similar. They generally divide it into four steps: learn a concept, teach it to others, identify gaps in your understanding, and simplify it with an analogy. Teaching someone else so they understand means explaining what you’ve learned in a way they can follow. Only then have you really learned it. That is the core of the Feynman Learning Method: by thinking about how to help you understand, I indirectly make myself truly understand it—and understand it more deeply.
The underlying principle is that knowledge must be output after it has been input and absorbed for the learning process to be complete. Without output, you have only seen or heard the knowledge, which at most lets your brain know about it. The Feynman Learning Method calls for explaining knowledge in our own words to someone else, bringing that person’s brain to the point of knowing it. Only then can we say we have learned it ourselves.
If you rank all the main learning methods by how well they help you absorb knowledge, teaching others is the best, because teaching is the sum of all the learning steps. To teach someone,
you first have to understand it yourself—that's learning the basics by listening and watching. You have to take some responsibility and be as thorough and accurate as possible, which means verifying facts and filling in gaps—that gives you review and consolidation.
You have to explain the knowledge clearly, give a few vivid examples, make a few apt analogies, and use gestures and discussion to deepen your understanding. Explaining it clearly isn't enough—you also have to help the other person grasp the key points and understand it better. That forces you to simplify complexity,
as for concept review, simplification, demonstration, hands-on practice, and discussion—all these steps come into play naturally when you teach someone, so there's no need to waste brain cells deliberately memorizing them. Just remember the essence of the Feynman learning method: teach someone else and find a way to make them understand. In fact, truly internalizing knowledge and making it your own is laborious and slow—no effort means no impression, and no slowness means no solid foundation. So the Feynman (feiman) learning method—'fei' for effortful and 'man' for slow—is the ultimate end.