“I’m sure. But look at it this way. What really is the point of trying to teach anything to anybody?”

This question seemed to provoke a murmur of sympathetic approval from up and down the table.

Richard continued, “What I mean is that if you really want to understand something, the best way is to try and explain it to someone else. That forces you to sort it out in your own mind. And the more slow and dim-witted your pupil, the more you have to break things down into more and more simple ideas. […] The teacher usually learns more than the pupil. Isn’t that true?”

Dirk Gently’s Holistic Detective Agency, Douglas Adams.