Zac Efron  turns 27 on Saturday, and his birthday has us reminiscing about his breakout role as Troy Bolton Disney's 2006 movie, High School Musical, and its two epic sequels. It marked the first time we ever swooned over Zac and his singing, dancing, and smirking skills — sometimes while shirtless . To celebrate his birthday, not only did we round up all his hottest movie pictures  and put together 74 crucial moments in our decade-long crush on Efron , we unearthed 12 GIFs that represent our first impressions of him. Are you sitting down, Wildcats? Because things are about to get steamy in here. You can bet on it.