Flow
Everyone has heard of Flow. The literature on Flow comes primarily from a lifetime of global research by Mihaly Csikszentmihalyi (pronounced Me-high Chick-sent-me-high). He says: Thirty years of research and 18 books later, I have proved that the most obvious component of happiness is intense concentration. Intense concentration comes when a Challenge is matched by an Ability. When challenge and ability meet like this, it puts us into a Flow