[The Egyptian leader Amasis answered] Men who possess bows bend them only when they need to use them. If bows were bent all the time, they would break and would therefore be of no use when needed. This is also the nature of a man: if he wanted to work hard all the time and never allowed himself time to play, he would go mad without knowing it, or have a stroke. Knowing this well, I give each activity its turn.

source: Herodotus, Histories 2.173 tags: Work, Leisure