Grow Up: Actors Who Played Younger ... Way Younger

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They say that high school is never really over, and it would appear that some aging actors take the adage very seriously.

The trailer for Justin Timberlake and Ben Affleck's upcoming film "Runner, Runner" premiered yesterday, and our favorite *NSYNCer finds himself regressing to those frosted tip days of youth. Mr. Timberlake plays Richie, a spritely Princeton student who finds himself in deep financial heat. Richie is probably college age (18-22), which makes Timberlake, 32, at least 10 years older than his character.

This baffling case of cinematic time travel got us thinking: What other stars have deceived us and played younger characters when they were in fact not that young at all? We did a little digging, and the findings made our 18-year-old (but actually 34, oops) hearts skip a beat.

10. Rachel McAdams as Regina George in "Mean Girls"

Regina's age: 16-17

Rachel's age at the time: 26

One of pop culture's greatest high school villains was actually a decade out of high school.

9. Tobey Maguire as Peter Parker in "Spider-Man"

Peter's age: 17-18

Tobey's age at the time: 27

When Peter was slinging "spidey webs" all over New York City, Maguire was three years shy of turning the big 3-0.

8. Judd Nelson as John Bender in "The Breakfast Club"

John's age: High school (15-18)

Judd's age at the time: 25

We wonder whether Judd Nelson even remembered detention.

7. Channing Tatum as Duke Orsino in "She's the Man"

Duke's age: High school (15-18)

Channing's age at the time: 26

The high school sophomore in us died a little bit when we found out dating sexy-soccer-Channing could have legal consequences.

6. Jennifer Grey as Frances "Baby" Houseman in "Dirty Dancing"

Baby's age: High school (15-18)

Jennifer's age at the time: 27

A baby she was not.

5. Cory Monteith as Finn Hudson in "Glee: The 3D Concert Movie"

Finn's age: 18

Cory's age at the time: 29

Looks like Monteith enjoyed the glee club so much he decided to stay for a bit longer...11 years longer.

4. Paul Rust as Denis Cooverman in "I Love You, Beth Cooper"

Denis's age: 17-18

Paul's age at the time: 28

It takes guts to declare your love for Hayden Panettiere at any age, even 28. You go, Mr. Rust. You go.

3. Justin Long as Bartleby Gaines in "Accepted"

Bartleby's age: 17-19

Justin's age at the time: 28

Bartleby was trying to get into an undergrad program when Long was the age of a medical school student.

2. Jesse Metcalfe as John Tucker in "John Tucker Must Die"

John's age: High school (15-18)

Jesse's age at the time: 28

John Tucker must die? No...John Tucker must graduate.

1. Sissy Spacek as Carrie White in "Carrie"

Carrie's age: High school (15-18)

Sissy's age at the time: 27

Spacek's youthful appearance made her an easily believable high school student. We aren't going to say anything mean because... well, she's Carrie.