What ultimately is the power of storytelling?

In “Good Form,” the narrator steps back from the war stories and tells the reader concrete details about his own life. Tim O’Brien is 43 years old, he writes. O’Brien is a writer and a veteran of the Vietnam War. Everything else is invented, he says. O’Brien saw a young man die in Vietnam. The man’s eye became a star shaped hole, he writes. But O’Brien himself did not kill the man. Not having killed the man is the “happening-truth” writes O’Brien. Or perhaps he did kill the man. That is the “story-truth.”

Because of the difference between “story-truth” and “happening-truth", O'Brien can tell his daughter, Kathleen, with equal certainty that he has both killed someone and never killed anyone. Both are honest statements in his eyes.