in chapter 3 what caused the youth to begin to reflect on the situation he was in

The men are ordered to get up and march at lightning. They hear bullets and explosions in the distance. The men begin to run frantically. They are dropping their gear and Henry realizes his predicament. He feels trapped in a vortex of confusion. Henry sees his first dead man; he tries to find his lifeless eyes and the truth of war begins to seep into his bones.