It seems like just yesterday we were singing along to "Get'cha Head in the Game," and trying out crème brûlée recipes while watching High School Musical. Or maybe it actually was yesterday, since we totally just re-watched the movie in honor of Ashley Tisdale's 29th (!!!) birthday! We weren't the only ones having a mini-HSM throwback moment: Zac Efron shared adorable reunion pics of him and Ashley on his Instagram page in honor of her big day. They look so different now than they did when they were playing Troy and Sharpay in 2006.
Since it's Throwback Thursday, we rounded up our fave HSM stars' red carpet pics from when the movie first debuted and contrasted their styles to how they dress now! Your jaw will drop when you see how much stars like Vanessa Hudgens and Corbin Bleu have re-vamped their looks.
Click through the gallery above for incredible then-and-now pics of your favorite HSM stars! Which celeb's style change shocked you the most? Tell us what you think in the comments section below.