I drag myself to the gym like a shift worker dragging himself to the factory. I limp onto the mat feeling tired and old, and after I warm up and get going . . . I have so much fun. The blubbery, congested sensation of incipient middle age gives way, and I feel young again, and strong. When I've competed well, and especially when I've held my own in the sparring, I leave the gym feeling so awake, my whole system revving with something purer than a runner's high. I drive home knowing that I've been going through life half asleep, and I feel a euphoric gratitude for my living muscle and bone and blood.