War changes everyone involved in one way or another. For some, war changes them physically because they become physically deformed, but for most people, war changes their mental state. War changes the mental state of people because of the duties they have to perform and the experiences they have to go through. Tim O'Brien shows how the mental state of the characters changed throughout the book, due to the war. In the story "How to Tell a True War Story", Bob "Rat" Kiley loses his best friend, Curt Lemon, right in front of him to a land mine. Rat Kiley is very sad because he lost his best friend: “And then the letter becomes very sad and serious. Rat pours out. He said he liked this guy. He says this guy was his best friend in the world. TheyIn the story When Mary Anne first arrives in Vietnam, she is the typical American girl of the time. She was innocent, pure and full of energy. “Sometimes she gave off a kind of go-go, shy, flirtatious energy, but apparently that never bothered Mark Fossie” (O'Brien, 95). Mary was like this because she didn't know anything about war, so she didn't think war was that bad. After a while, she wanted to know more about the war and the land because she found it fascinating: “The war intrigued her. The land too and the mystery” (O’Brien, 96). She wanted to learn more because it matched her interests. Later in her hospital stay, she began helping when wounded arrived: “At the end of the second week, when four wounded arrived, Mary Anne was not afraid to get her hands covered in blood. Sometimes, in fact, she seemed fascinated by it” (O’Brien, 97-98). She was fascinated by it because she liked having hands-on experience. Towards the end of the story, Mary has become a full-fledged soldier. She accompanies the Green Berets in their patrols and ambushes, “Ambush. All night, man, Mary Anne is in fucking ambush” (O’Brien, 102). She accompanies the Green Berets on their patrols and ambushes because she feels the need to see what the war was like and not just hear stories about what it was like. At the end of the novel, Norman makes up these scenarios about what he would tell someone about how he almost got the Silver Star. He made one up for his father and Sally Kramer, who was an old friend. He makes up scenarios because that's how he copes with the war and when he could have gotten the Silver Star. What changed Norman Bowker's mental state and sent him running in circles around the lake was the death of one of his friends and fellow soldier, Kiowa. “He pulled hard but Kiowa was gone, and then suddenly he felt himself go. , too” (O’Brien, 149). This death changed him more than the others because he thought he could save him, but he couldn't. Norman felt responsible for Kiowa's death because Norman couldn't take Kiowa out of the world.