I learn something every time I listen to Robert Greene. I've read all of his books, and reread them at regular intervals.
Robert Greene is not your typical self-help guru. (Most of them rely on mere "positive thinking" and empty generalizations.)
Greene studies a diverse range of fields--from history to psychology--to distill the best tools for self-mastery and external success.
I highly recommend that you read Robert Greene's books, if you have not done so already.