I find it fascinating that Zen/Tao "teachings" for thousands of years have focused on what seems to be one of the most difficult areas of human existence: "man vs. himself".
Modern cognitive therapy seems to be an institutionalized version of the whole Zen thing which I find amusing. Personally I've never been happier once I realized that the world is literally what you make of it, that is, it is all up to your internal interpretation.
Once you realize that your mind is constantly interpreting everything, you can learn - through practice and meditation - to just be however you want to be and be in complete control of yourself.
Because in the end... you're just being... unless you're not and then it doesn't matter.