Today marks something rather important for Zac Efron: it's his 29th birthday. That's right, the heartthrob has officially entered the last year of his 20s, which tbh, is kind of hard to believe! But there is one role that will forever hold a special place in so many people's hearts: Troy Bolton, the star basketball player who just so happens to have a lovely singing voice in High School Musical. There really isn't anymore better suited for a part in a musical movie like Zac was for Troy and as everyone knows, that series of movies are nothing short of iconic. In honor of Zac's special day, we decided to take a trip down memory lane, since he first transformed into Troy 10 years ago.
Click through the gallery to see the transformations of tons of the lead guys from your fave Disney Channel Original Movies. Warning: you're totally going to be hit with a wave of nostalgia, especially when you see how much these cuties have all grown up. Then drop a comment below telling us which of these DCOMs is your fave!