My attitude is never to be satisfied never enough never.
What's important at the grocery store is just as important in engines or medical systems. If the customer isn't satisfied if the stuff is getting stale if the shelf isn't right or if the offerings aren't right it's the same thing. You manage it like a small organization. You don't get hung up on zeros.
Open your eyes look within. Are you satisfied with the life you're living?
You must never be satisfied with losing. You must get angry terribly angry about losing. But the mark of the good loser is that he takes his anger out on himself and not his victorious opponents or on his teammates.