Finished this one a few days ago.
Eckhart Tolle - The Power of Now
Will help improve game.
Will help you find inner joy - as opposed to the mind created pleasure and pain.
An absolute must read for EVERYBODY.
One point, tho: Some of the concepts I understood because I had watched the tolle videos on YouTube. I'd say watch the videos first because I know for a fact that some revelatory points Tolle makes would not have sunk in so deeply had I not watched the videos first.
HIGHLY RECOMMENDED BOOK!