Zac Efron is all grown up. And he knows exactly how to prove it.

“Eventually I’ll be getting to adult-adult (entertainment), for real. But baby steps,” the actor deadpans.

Don’t fret, Efronistas. He’s only kidding. Efron, 22, still remains his wholesome, hunky self. But the actor with the gleaming blue eyes and immaculately spiked hair, who broke through as studly varsity basketball captain Troy Bolton in Disney’s “High School Musical” trilogy, is gradually scoring more mature roles.

On Friday, he headlines the drama “Charlie St. Cloud,” a family flick starring Efron as a sailing prodigy with a scholarship to Stanford whose entire future collapses amid the accidental death of his beloved younger brother. And the film, which deals with debilitating isolation and loss, has nary a musical number, which is one of the many reasons the project resonated with Efron.

“It seemed like someone I could play. There were a lot of scripts I was getting with guys that were too cool, you know? Not only am I not that person, why would I pretend to be that person?” Efron says. “Charlie was a character I felt I could bring something to. Having a little brother, having goals and aspirations, loving sports, all that kind of stuff just made sense to me. For me, a huge part of my life is family, my mom and dad and brother. Charlie St. Cloud was a chance for me to dream and say, ‘What if I didn’t have that?’” [Continue reading and watch the video]