I've learned many important lessons so far, but the most important may be the concept of the hot lunch. It's very easy to get wrapped up in the walking, only stopping momentarily at views that really deserve an hour's contemplation. This both detracts from the scenery and exhausts the body. Finding a spot to lay down the pack, pull out the stove, and make a real meal for lunch (even if it's ramen or a pack of oatmeal) gives you the opportunity to enjoy the scenery, rest your legs, and restore your energy.
Coming out of the hundred mile wilderness, I sat on the Barren Ledges, ate some delicious Annie's mac and cheese, and watched a group of three large birds soar higher and higher on thermals out of the valley while looking at this:
It's definitely important to keep walking, but it's far more important to stop and look around sometimes!