This is a very important point. Because of the "curse of knowledge", at a certain point you are unable to communicate the subject you're expert in to beginners.

This is a very important point. Because of the "curse of knowledge", at a certain point you are unable to communicate the subject you're expert in to beginners. That's why one of the best ways to study is with your peers: the one who gets it first has the best chances to transmit their aha moment to their colleagues. It's difficult because to get to the level of a beginner you need to force yourselves to make many oversimplifications, moreover, you have to deliberately be imprecise otherwise people won't understand you. But some people do have this talent: even though they are experts, they still can transmit their knowledge at various levels of difficulty. Keith Devlin is one. Feynman of course.