Happy birthday, Zac Efron!

My, how you've grown... The actor, who turns 31 on Thursday, sure has come a long way since he rose to fame with his starring role in the 2006 Disney Original Movie High School Musical. His portrayal of student, basketball star and your imaginary boyfriend Troy Bolton captured millions of hearts and turned him into one of the most sought-after actors in Hollywood.

And if we're about to get all nostalgic on you, can you believe High School Musical 3: Senior Year, the last movie starring the original cast and the first to be released in theaters, will celebrate its 10th anniversary on October 24?

See how Efron, Vanessa HudgensAshley Tisdale and the rest of the stars have changed over the years and find out what they've been up to.

High School Musical, Then and Now, Zac Efron, Vanessa Hudgens

Disney

High School Musical, Then and Now, Zac Efron

Disney/WireImage

High School Musical, Then and Now, Vanessa Hudgens

Disney/Getty Images

High School Musical, Then and Now, Ashley Tisdale

Disney/Getty Images

High School Musical, Then and Now, Lucas Grabeel

Disney/Getty Images

High School Musical, Then and Now, Corbin Bleu

Disney/Getty Images

High School Musical, Then and Now, Monique Coleman

Disney/Getty Images

High School Musical, Then and Now, Bart Johnson

Disney/Getty Images

High School Musical, Then and Now, Chris Warren

Disney/ABC

High School Musical, Then and Now, Alyson Reed

Disney/Getty Images

High School Musical, Then and Now, Olesya Rulin

Disney/ABC

High School Musical, Then and Now, Kaycee Stroh

Disney/Getty Images

High School Musical, Then and Now, Jemma McKenzie-Brown

Disney/Instagram

Go....Wildcats!

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