Somehow this reminds me of my old physics professor, who often had simplistic, almost boring explanations of things, like jiggling atoms making friends with each other, or how a train stays on the track.

His name was Richard Feynman.

https://www.youtube.com/watch?v=nYg6jzotiAc

(Highly recommended video.)

I should also note that "teach me something" was intended to give the candidate a chance to be the expert at the beginning the interview.

It wasn't something they would be judged on, it was an ice-breaker. And a fun one, based on the feedback I got from candidates.