Have you ever been watching a movie or television show and wondered how old the actors actually were? Sometimes, they don't really look young enough to play a high schooler! Or at times, perhaps they fooled you because they looked so young. We rounded up a list of some actors who played a character in high school and we will tell you how old they actually were at the time of filming. See if you can guess any of their real ages as you think back and remember their character. 1. Olivia Newton-John Sandy \/ Paramount Pictures Olivia Newton-John played the iconic Sandy in Grease. Sandy was supposed to be a senior in high school. Sandy was 18, but Olivia was actually 29 years old when she filmed this classic film. Sadly, Olivia Newton-John is currently going through cancer. Find out how she is doing now. 2. Stockard Channing Rizzo \/ Paramount Pictures Continuing on with Grease characters, Stockard Channing played Rizzo. Rizzo was also 18 years old, but Stockard was 34 at the time! Who knew? 3. Henry Winkler Fonzie \/ Wikimedia Commons Henry Winkler hit it big time playing Fonzie on Happy Days. Fonzie was in high school, but Henry was 29 years old at the time he started playing the Fonz. 4. Sissy Spacek 'Carrie' \/ MGM Sissy is known for playing the role of Carrie in the film by the same name. While Carrie White was only 16 years old, Sissy was 27 when she starred in the movie. Read onto the NEXT page for even more stars who played high schoolers but were WAY older! 5. Jennifer Grey and Patrick Swayze 'Dirty Dancing' \/ Great American Films Limited Partnership When Jennifer Grey was in Dirty Dancing with Patrick Swayze, her character Baby was only 17. Jennifer was 27 at the time of filming. Patrick was supposed to be 25 in the movie, but he was 34 in real life. 6. Winona Ryder Susanna Kayson \/ Columbia Pictures Winona Ryder starred in Girl, Interrupted. Her character Susanna Kayson was 18 years old, but Winona was a decade older at the time of filming. 7. Alan Ruck Cameron \/ Paramount Pictures Alan Ruck starred as Cameron in Ferris Bueller's Day Off. While Cameron was 17 years old and in high school, Alan was actually 30 at the time. 8. Gabrielle Carteris Gabrielle Carteris \/ Fox During the original Beverly Hills, 90210, Gabrielle played 16-year-old Andrea Zuckerman. She was actually 29, not a high schooler! Did any of these ages surprise you? Learn why fans are not that pleased with the '90210' remake with some of the original cast.