When the Tao prevails in the world, fast horses do slow work in the field. When the world is without Tao, horses are bred for war.
There is no greater misfortune than not knowing what is enough. There is no greater fault than the desire to possess.
Therefore, if you are satisfied that what you have is enough, you will always be content!
(from Tao Te Ching, verse 46, translation by Robert Brookes)