When 13 Going on 30 premiered in 2004, it made hearts swoon! The quintessential romantic comedy starred Mark Ruffalo and Jennifer Garner, but there were a few other now-famous faces in the film. It took 15 years for Mark to find out that his Avengers: Endgame costar Brie Larson also starred in the movie! Scroll through to see Mark's reaction and to learn which other child stars made their big-screen debuts in the flick!
Mark, 51, was attending the Avengers: Endgame premiere on Tuesday, April 23, when he learned the news. “She was a mean girl! Oh my God, that’s amazing. Wow, I didn’t know that,” he laughed.
Turns out Brie played the role of "Six Chick" in the film. But there are a few other young stars who also made appearances.
Pretty Little Liars alum Ashley Benson portrayed a "Six Chick," while Secret Life of The American Teenager star Renee Olstead was cast in a small role.
Revenge star Christa B. Allen starred as the younger version of Jennifer's character. The 27-year-old would then go on to play the teen version of her again in 2009's Ghosts of Girlfriends Past.
The iconic film celebrated its 15th anniversary on April 23 and Jennifer paid tribute with a sweet Instagram post.
Are you surprised to find out that Brie was in the film? Sound off in the comments below!