In 2003 David Miller is 41 with a wife and three young daughters. He rejects his computer programming job, and with the consent of his family, starts up the AT. Thus the title.
Near the midpoint of the story, there is a quote: "too much hard work, too much pain, too much time away from my family ..." but he continues. This is a success story. Though he does not say so, David is one of the stronger AT thru-hikers, big miles, day after day. All the usual injuries occur, but these are endured, rather than used as a reason to leave the trail. There is a community of hikers, and the sharing of intense experiences day after day is almost addictive
The reader begins to get a feel for the rituals of shelters and in trail towns. After reading the book, a potential AT hiker should feel much more comfortable with what they are going to encounter. As I read the book, I kept visualizing the AT trails vs the ones I have hiked in California and in Europe - the AT seems much more difficult, though you have more frequent opportunities to get off the trail.
The overall tone of the book is strongly positive. That's a little difficult to explain, since there is a lot about hardship, but trust me, you will understand when you read it.
I recommend this to any long distance hiker, and particularly to someone planning to walk the Appalachian Trail.