Lately I have been doing more reading of books that can be applied to Jiu Jitsu, that are not necessarily about Jiu Jitsu. Math and physics books, logic and philosophy, teaching and learning styles, etc.
Has anyone found some good books that they would like to recommend? Something off the beaten track, more esoteric, than regular jiu jitsu "how to" books?
I'd love to do some more reading on my Summer break.