Walking, done far enough, stops being exercise and becomes something closer to a discipline of the mind. The Warrior Walker sits at exactly that junction, filed at once under memoir, wellbeing, personal development and the outdoors, which is less a filing error than an accurate description of what the book does.
Paul Harris tells it from the inside, and the fact that the recording is read by the author rather than a hired voice changes its character entirely: the pauses land where lived experience puts them, not where a script suggests they should. Listeners who come for the physical challenge tend to stay for the harder material underneath it, the part about why anyone would keep going.