In Saving Private Ryan, all main actors went through army training except Matt Damon so that the other actors would show resentment for him.

Before filming began, several of the film’s stars, including Edward Burns, Barry Pepper, Vin Diesel, Adam Goldberg, Giovanni Ribisi, and Tom Hanks, endured ten days of “boot camp” training led by Marine veteran Dale Dye and Warriors, Inc., a California-based company that specializes in training actors for realistic military portrayals. Matt Damon was intentionally not brought into the camp, to make the rest of the group feel resentment towards the character.

Fun fact: The story he tells at the end about his last night with his brothers was made up on the spot…which created a continuity error in the film. He’s says at the end of the story that one of his brothers went off to basic the next day and that was the last time the four of them were together. But when they showed his home at the beginning when his mother gets the news, there’s a picture of the four brothers…all in uniform.