Legendary Hungarian-American psychologist Mihaly Csikszentmihalyi is best known for identifying and naming the concept of 'flow' — a state of complete absorption in a challenging and intrinsically rewarding activity that he describes as the optimal human experience. His research demonstrated that flow is the psychological hallmark of play at its richest, and that designing life and work to enable flow states is the most reliable path to genuine happiness. Professor emeritus at Claremont Graduate University, he was widely regarded as the world's leading researcher in positive psychology until his death in October 2021.