At Wal-Mart, a co-worker once advised me that, although I had a lot to learn, it was also important not to "know too much," or at least never to reveal one's full abilities to management, because "the more they think you can do, the more they'll use you and abuse you." My mentors in these matters were not lazy; they just understood that there are few or no rewards for heroic performance. The trick lies in figuring out how to budget your energy so there'll be some left over for the next day.