Contrary to our usual conceptions of using one’s “skills to the utmost,” Csikszentmihalyi tells us that the reward for entering such a state is not the material benefits it generates, but the positive emotions.

These, as Einstein theorized, not only motivate us to become better, but they also provide a source of meaning no amount of financial gain above a minimum level can offer.

Einstein understood the value of developing an informal avocation. “Mainly play the things on the piano which please you,” he tells his son, “even if the teacher does not assign those.”

Doing what you love, the way y...