Because when you think about it, people are happiest when in flow, when they're absorbed in something out in the world, when they're with other people, when they're active, engaged in sports, focusing on a loved one, learning, having sex, whatever.
人们最开心的时候是当他们处于心流之中 醉心于外界的某项活动中 与别人相处 身体动起来 做运动 专情于某人 学习 性生活 等等