Tim O'briens mental state

Tim O'brien was on a mission when he saw a Vietnamese man walking with a weapon, he perceived the man as a threat so out of instinct he pulled the pin from his grenade and threw it at the man. The soldier exploded leaving a star shaped hole in his head and his body looked like ground oats. This event really messed Tim up mentally. Seeing the extremely graphic death of the man gave him really bad PTSD.