The small town life
The small town where Homer lives is a specific kind of imagery that could include all of America during the war. The town is small, though, so they have the added benefit of knowing all the people in the town, which is especially helpful when they start receiving the news that their loved ones are dying abroad. The young boy delivers the news as a telegraph boy, making him the bearer of bad news in a town where eventually, people stop wanting to see him, because he brings the news of death.
Adolescence and growth
Homer is just a kid growing up. He has a crush at school, and in gym he is competitive, often trying to establish himself as a prime candidate for girls, especially Helen. He grows through the novel, and eventually, his adolescence ends, because he receives the news that his brother has died and now he must guide the family and provide for them, because his other siblings are young, and his mother is unable to work and take care of them.
Desire and mourning
Homer encounters death on a daily basis, because he delivers telegraphs about people dying in war, and because he has a brother who is at war, and most importantly, because his father has already died. He works hard because he knows that he is responsible to help his family, because death has robbed them of so much. They mourn together both as a family and as a community, because the war takes the lives of many boys from throughout the town.
Change and experience
Metaphysically, one could say that what Homer really struggles to understand in this novel is time and the way that time brings change so involuntarily. There is nothing he can do to rewind his father's death, nor can he help his brother. When Marcus dies, he is forced to experience the war for its painful reality, through personal experience, so that by the end of the novel, he sees that there is nothing he can do to control life, but rather, through experience he can survive and provide for his family in whatever limited ways are available to him.
