Best, and most scientific [0] book in this regard: "the emotional life of your brain" by Richard J. Davidson. One of the TLDR: the feeling of being happy and b

Best, and most scientific [0] book in this regard: "the emotional life of your brain" by Richard J. Davidson. One of the TLDR: the feeling of being happy and being sad are not the same brain-function with a sign reversed. Just because you're not happy doesn't imply you are sad and vice versa, just because you're not sad doesn't imply you're happy. You have to train not-being-sad and being-happy independently! [0] every hypothesis was experimentally tested!