The earth is like a spaceship that didn't come with an operating manual.
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.
Every time a football player goes to ply his trade he's got to play from the ground up -- from the soles of his feet right up to his head. Every inch of him has to play. Some guys play with their heads. That's OK You've got to be smart to be number one in any business. But more importantly, you've got to play with your heart, with every fiber of your body. If you're lucky enough to find a guy with a lot of head and a lot of heart, he's never going to come off the field second.