Puzzle play

In volume 4 of The World of Mathematics (James R Newman, Editor; Dover 2003), in a section entitled "Amusements, Puzzles, and Fancies," is an essay by Edward Kasner and James R. Newman entitled "Pastimes of Past and Present Times." This piece is prefaced by a quote from Mark Twain: "Work consists of whatever a body is obliged to do, and play consists of whatever a body is not obliged to do." One of the characteristics that mathematicians and poets have in common  is that both enjoy mind-play -- mental adventures with ideas or numbers or words, dancing and shaping into some new thing.