This highlights the guilt he feels for killing the young man and basically talks about himself when he makes up this person's life story because O'Brien says "the when I was young I wouldn't have wanted to be a soldier" and in the chapter "On a Rainy River" he tells us that he never wanted to go to war and that he almost ran away to Canada. Specifically, O'Brien sees this man as himself, as what he would turn into if he lost his life in war. In his fantasy of what the young man's life was like, he finds similarities, and these similarities are not wanting to be at war and the fear of shame if you don't go to war, which was a defeat.