An Appalachian Pilgrimage
I have read numerous books on thruhiking in the past year-and-a-half and, besides A Walk in the Woods for its amusing and witty qualities, On the Beaten Path is hands down the most informative and honest portrayal of what a reader like myself (a non-hiker) would imagine an average personal transformation would be on such an arduous and difficult journey.
Rubin describes what the daily grind is like on the trail. It is truly fascinating to watch the change in him as he hikes for the many months on the Appalachain Trail. It is not just the physical change, but the mental change and how the anti-stimulous of being alone (with various hiking "partners" peppered through the route) and the stimulous of the environment and Nature play on the psyche that is intriguing.
I would argue that most people that write a book about the subject of their hike write the book because of how the hike changed them. Maybe it doesn't change everyone. The sheer extreme nature of walking with a 30-50 pound pack for thousands of miles would certainly test mental and physical stamina in even the most athletic and mentally stable of each of us - that is for sure.
For Rubin the hike seemed for fortify his own love of solitude and Nature.