Flow is defined as the state in which people are so involved in an activity that nothing else seems to matter; the experience itself is so enjoyable that people will do it even at great cost, for the sheer sake of doing it. It is one of the key concepts in positive psychology. Developed by Mihaly Csikszentmihalyi and his colleagues starting in 1980s, a lot of research has been done to explore how flow happens in various domains such as sports, education, work and leisure. Mihaly Csikszentmihalyi has presented this research in this book in a language that can be understood by laymen like us. Though the book runs over some 300 pages, it takes time to read and absorb the concepts discussed in this book. A recommended reading for a person who is interested in positive psychology.