Hans Selye

Find your own stress level — the speed at which you can run toward your own goal. Make sure that both the stress level and the goal are really your own, and not imposed upon you by society, for only you yourself can know what you want and how fast you can accomplish it. There is no point in forcing a turtle to run like a racehorse or in preventing a racehorse from running faster than a turtle because of some 'moral obligation.' The same is true of people.
-Hans Selye