Musashi is Japan's most famous swordsman, from the peak of the Samurai era (early 1600's). His life is chronicled very well by Yoshikawa. There are some good notes in Victor Harris' introduction. Anyway, when he got old, he went and lived in a cave, and wrote this classic book of strategy, which every Japanese businessman allegedly reads all the time. It's full of esoteric advice like (paraphrased) assume the position and don't let your enemy beat you and keep your mind where it should be and practice hard.

I probably need to check this out again now that I'm older and wiser. Maybe I'm smart enough now that I'll find it better.