Excellent book and theories that explores that happiness comes when a person is doing what they enjoy and what fulfills them while helping people or giving something back to society at the same time.
“What really makes people glad to be alive? What are the inner experiences that make life worthwhile? For more than two decades Mihaly Csikszentmihalyi studied those states in which people report feelings of concentration and deep enjoyment. His studies revealed that what makes experience genuinely satisfying is ‘flow’ – a state of concentration so focused that it amounts to complete absorption in an activity and results in the achievement of a perfect state of happiness.”