Mornings are glorious, a new day is starting and there are endless possibilities. You can get up and beat the sun out the door, waking it up, and saying "Come on you lazy fuck, let's get rolling."
18, 20, 50 or however many miles out in, and you roll on to your driveway tired and at the same time, refreshed. You just did something that most people wouldn't, and you did it before most of them are even awake. It's not a smug satisfaction, but a knowledge of the fact that the race isn't won by those asleep, but by those who are willing to greet the day with vigor and make the most of it.