World War I Soldier Poets

It's is amazing to me that a man in the trenches, so disgusting it is impossible to imagine them for someone who has not experienced them, write poetry like they have been doing it all their life. Men who look death in the face every day, write to their families and loved ones to not mourn for them when they are gone, but to move on. They write of sadness, chaos and products of war. You can really feel what they were trying to say through their straight forwardness of their writings. It escapes me how one who had faced such monstroncities, create such poetry as "When I'm Killed" by Robert Graves and "The Dragon and the Undying".