There's much to be said for feeling numb. Time passes more quickly. You eat less and because numbness encourages laziness you do fewer things good or bad and the world's probably a better place for it.
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.