that's interesting, i do something similar when helping my 16 year old with his homework. I ask him to teach me the topic first (it's been a while since i took physics and calc hah). By the time he's able to answer my questions so that i can help him then he's answered his own questions pretty much.

I do this at work too. When doing code review i actually do mostly listening and then some questions. If the developer can teach me the code and i understand what they're doing and why then it's usually pretty good code already.