On Sep 6, 2008, at 11:30 AM, Prabhu Ramachandran wrote:

This is true in many other fields too. For example teaching is one of the best ways to learn for precisely the same reason. When you try to teach (well!) you try to go beyond just learning the details. The same happens when you explain something you think you know well to someone else, you see something you sometimes haven't and go "Aha!".

My dad has always said that if you really understand something, you should be able to teach it to a bunch of undergrads.