Audie Murphy???
That may explain why most of Audie Murphy's later movies were westerns. After you've been there, done that, making a movie about it probably either seems dull or just a way to relive the parts you don't want to think about all the time.
Had to search - Audie Murphy Autobiography - “To Hell and Back”.
He was cast as himself in a WWII role and the director wanted to do it exactly as his exploits had happened. Murphy said something like “If you tell it like it really happened, nobody will believe it.”