There's a reason filmmakers rarely cast actual teenagers. Real adolescence is full of insecurity, change, stickiness, and other things no one actually wants to see on a big screen. However, there's a fine line between comfortably post-pubescent and an obviously receding hairline. Here's seven actors who were simply too old to play high school.

Judd Nelson – Breakfast Club
Movie Age: 17 / Actual Age: 26
It's OK that Judd Nelson's classic bad boy looks a few years older than his naive peers. It's not OK that he looks like he's been drinking and smoking heavily for the past two decades. Through no fault of Judd's, the fingerless gloves and endlessly layered flannel all reek of a guy a little too old trying a little too hard.

Harland Williams – Sorority Boys
Movie Age: 25, if we're being generous. / Actual Age: 40

Casting Director: "Sir, I'm sorry, we've sent offers to every comedian in Hollywood, no one wants to be in this movie." Producer: "No one?" Casting: "Well, the guy from Rocket Man's available, but, I mean, he's old enough to be these kids' dad." Producer: "Fuck it, we're not making Citizen Kane here. Book him."

Richard Dreyfuss – American Graffiti
Movie Age: 18 / Actual Age: 26
Thanks to a rare, Benjamin Buttons-esque condition, Richard Dreyfuss has spent the majority of his life as a fifty-five year-old man. So while it's strange to see him play high school, stranger still is that the film is a period piece, set a decade earlier in 1962 when Dreyfuss was actually finishing high school. With such quixotic casting, no wonder the only other thing on the director's resume is some silly fantasy movie. 

Eric Christian Olsen – Not Another Teen Movie, The Hot Chick, Dumb and Dumberer, Fired Up
Story goes, an old gypsy witch was so infuriated by Olsen's performance in Not Another Teen Movie that she cursed him, dooming him to become that which he had mocked. (The witch was a big She's All That fan.) In any case, the irony came full circle this year, when 32-year-old Olsen played a vain high school football star in Fired Up, a non-parody version of the role that gave him his start almost a decade ago.

Stockard Channing – Grease
Movie Age: 17 / Actual Age: 33
Given the actual skills needed to be in a musical, it's understandable producers would want to cast more seasoned performers. (To anyone who brings up High School Musical, just… no.) However, not only was Channing aggressively attacking her mid-30s when the film came out, she was already on her second marriage. Singing/dancing? Yes. Remotely convincing teen angst? Not a chance.

Tom Hanks – Forrest Gump
Movie Age: 15 / Actual Age: 38

If biopics like Ray and Walk the Line have taught us anything about historical figures, it's that, after puberty, they remain stuck in their early-to-mid thirties for their entire life, pausing only occasionally to don unconvincing old-age make-up. Despite his fictional status, Forrest Gump is no exception, going from young tyke to Robin William's Jack in one brace-shattering montage.

Shannon Elizabeth – American Pie
Movie Age: 18 / Actual Age: 26
How outrageous is it that producers thought that, at the age of 26, Shannon Elizabeth could be remotely convincing as a Czech foreign exchange student? I mean, with her limited resume, what possible assets could she have brought to the- ah, right.

I bet she doesn't even speak Czech.