"It's youth blazing along on some kind of spectacularly high octane. It's like having a benign fever all the time. It's like being in love...It's the fever you live in that's the thing. The hot pulse of it all. The rest is just knickknacks and souvenirs. What you miss is the dizzy crazy lactic-acid storm of training, racing. The ten-milers laughing the whole way with guys who are your brothers in ways beyond genetics. The thousand quarter-mile intervals in the hot sun, grabbing your knees for balance afterward and rasping for air. Consuming huge mounds of fried anything-at-all and laughing at each other because you know not a molecule of it can stick to your slippery bones. And knowing nothing in your life will ever be that wild and alive again. No quest ever again as honorable or as noble."
excerpt, Once A Runner, John L. Parker Jr.