I thought about the teacher board, but this is also a general question.If you mention a concept to someone, how do you know they actually understood you or that you actually explained it in a way that's easy enough to understand? And how do you check for sure without being condescending? "Did you understand that? Really? Ok, then, explain it to me then."I heard a recording of myself talking about something. I botched the explanation. Lots of talking, but I doubt much if anything registered with the people I was talking to. So, what's the point of talking or explaining something? Why not mention less but make sure they actually understood it?