AceShowbiz - Charlize Theron still has no idea why Tom Hanks gave her a role in his 1996 film "That Thing You Do!" because she sucked at the audition. The actress admits she was starstruck and overwhelmed during her screen test as the girlfriend of leading man Tom Everett Scott's character, Guy, when she came face to face with her acting hero and flubbed her lines over and over.

Now a composed 42-year-old Oscar winner, the "Monster" star told chat show host Stephen Colbert she was a nervous teenager screwing up her lines when she auditioned for Hanks.

During an appearance on "The Late Show with Stephen Colbert" she recalled, "It was not good! I don't know why he (Hanks) gave me the role, I mean, honestly. I was so nervous. Imagine you're 19 and you meet this idol. I idolized him! I watched 'Turner and Hooch', like, 500 times. So to audition for somebody like that; it's frightening."

"The character who plays my boyfriend in the movie, his character name was Guy. I had to do this scene, and Tom read with me. It's so mortifying. I got so nervous that I couldn't say Guy and I kept saying 'gay,' and the more I tried to correct myself, the more I just said 'gay.' It was just so horrible," she added. "He literally said at one point, 'You know, let's just take a break. We'll come back'. And I was like, 'Ugh, I am sucking right now!' "