"Satisfaction is an emotion that captures the uniquely human need to impart meaning to one's activities," Berns concludes. "While you might find pleasure by happenstance--winning the lottery, possessing the genes for a sunny temperament, or having the luck not to live in poverty--satisfaction can arise only by the conscious decision to do something. And this makes all the difference in the world, because it is only your own actions for which you may take responsibility and credit."

--Gregory Berns, "Satisfaction", taken from here .

This makes a great deal of sense to me.