Matthieu Ricard, “the World’s Happiest Man,” told me that we should cultivate inner peace as a skill. “If you ruminate on sadness and negativity,” he explained, “it will reinforce a sense of sadness and negativity. But if you cultivate compassion, joy, and inner freedom, then you build up a kind of resilience, and you can face life with confidence.” When I asked him how we cultivate those skills, he said, “We train our brains. In the end, it is your mind that translates the outside world into happiness or misery.”