The Things They Carried "Sweetheart of the Song Tra Bong" pg 85-110

    In chapter “The Sweetheart of the Song Tra Bong” Rat Kiley, a soldier with a reputation for telling tall tales claims to have witnessed the transformation of Mary Anne Bell a typical American girl who visits her fiancé, Mark Fossie in Vietnam into a wild jungle beast.

"It wasn't a question of deceit. Just the opposite; he wanted to heat up the truth, to make it burn so hot that you would feel exactly what he felt."

Rat Kiley wasn't known for telling the truth so when he did it came across as a surprise and surprised all the soldiers. This explains why he doesn't always tell the truth as a story teller Rat wants to spice up the truth to make it more interesting.