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.
My mother enjoyed old age and because of her I've begun to enjoy parts of it too. So far I've had it good and am crumbling nicely.