"But what is work and what is not work? Is it work to dig, to carpenter, to plant trees, to fell trees, to ride, to fish, to hunt, to feed chickens, to play the piano, to take photographs, to build a house, to cook, to sew, to trim hats, to mend motor bicycles? All of these things are work to somebody, and all of them are play to somebody. There are in fact very few activities which cannot be classed either as work or play according as you choose to regard them."