An interesting and important insight by Mihaly Csikszentmihalyi is the following. We may sometimes be tempted to do our work with as little effort as possible. We try to cut corners and take shortcuts by avoiding challenge and complexity and get the work done in the easiest way possible. Often, we'd rather relax and be free than work and challenge ourselves. But Csikszentmihalyi's reasearch shows that seeking challenge and focusing on the complexity of our tasks is more likely to add to our fulfillment and happiness that relaxation and pleasure. You can read a bit more about these ideas in this review.