Everyone should read this two-volume set called Hiking The Appalachian Trail---
In Volume 2, a 17 year old kid named Eric Ryback thruhiked the AT in 1969. Here are two interesting quotes:
"Later, when I was arranging my equipment and food, people came up and questioned me about my trip. This was the first real indication I had that I was doing something unusual; they were amazed that I was able to maintain myself in the mountains for over 2 1/2 weeks with just what was in my pack, plus water from mountain streams." ERIC RYBACK
"Looking at that (resupply) food was one of my greatest pleasures on the whole trip. It was the last package I would pick up before I finished my trek. I wondered how I would make all of the food fit into the pack. It was for 20 days, the largest supply I had picked up. With the experience of 1,600 miles behind me, the heavier the pack, the more secure I felt. I knew I could go into the woods and stay for as long as the food lasted before coming back to civilization again." ERIC RYBACK