Our bodies have 35 trillion cells, trillion with a "T." We're talking national debt numbers here. (Laughter) Those cells turn themselves over once every eight years. And every time they turn themselves over there is some damage. And that damage builds up. And it builds up exponentially. It's a little bit like the days when we all had Beatles albums or Eagles albums and we'd make a copy of that on a cassette tape, and let our friends copy that cassette tape, and pretty soon, with successive generations that tape sounds like garbage. Well, the same things happen to our cells. That's why a 65-year-old person is aging at a rate of about 125 times faster than a 12-year-old person.