Kiowa started to sink into the muck after rounds of mortar fell onto the sewage field they were camping on. Norman Bowker tried to save him and pull him out but was unsuccessful. He thinks that he was as brave as he could've been, but still feels guilty because it wasn't enough to save him.
Man vs. Society
O'Brien feels extremely guilty after he kills a soldier with a grenade. He imagines the life the soldier had and would have had. He believes the soldier was just like him, innocent. He struggles between knowing he had to do it and knowing it was wrong.
O'Brien doesn't believe that the war is right and the country's reason for going to war isn't solid enough for killing. He goes to Canada with the thought of escaping the war, but runs into a conflict with society. He worries that if he doesn't go to war, his family and neighbors would look down on him for being a coward.
Curt Lemon fainted at the dentist from being afraid and was embarrassed. He wanted others to think he was a manly man, and he wanted to prove he wasn't a coward. So, he went back to the dentist at night and made him pull a perfectly healthy tooth.