It is surprising that this was originally published in 1990. I had to double check the dates in the opening pages because the concept of Flow is still discussed actively today; often quoted in other psychology books, one example is in Grit by Angela Duckworth . It also pops up in other mediums like podcasts, topics for life coaches/gurus, and in self-help and personal development book shelves. The TL;DR version is.. It is essentially about happiness. The argument being that if we want to maximize happiness, we should maximize Flow experiences. Now what is Flow? Mihaly Csikszentmihalyi defines it as: