Seventeen is a reverse-Big tale in which a man, played by 38-year-old Matthew Perry, somehow ends up in the body of a 17-year-old boy, played by Efron. “I’m essentially playing an old, kind of depressed middle-aged man,” Efron says. He still seems a bit shocked that the movie was created as a star vehicle for him.

“It’s weird,” he says, “but I don’t feel like I deserve any of the attention. There’s really nothing but one audition for a Disney Channel movie that separates me from 2,000 other brown-haired, blue-eyed guys in L.A., you know?”

Somewhere in the world, right this second, a little gay boy is making a plastic Zac Efron kiss another plastic Zac Efron. Bizarrely, the actor’s two biggest roles so far have both led to the same non-biodegradable immortality. The High School Musical “Troy Bolton” doll version of Zac Efron was followed by its own doppelgänger: the Hairspray “Link Larkin” doll version of Zac Efron.

“Zac is by far the biggest male personality in terms of driving interest and sales since Leonardo DiCaprio 10 years ago,” says Matthew Rettenmund, the editor-in-chief of Popstar!, a celebrity teen-pop magazine.

Both DiCaprio and Efron made their names with family-friendly TV (DiCaprio did 22 episodes of Growing Pains; Efron did 16 of the WB surf drama Summerland). DiCaprio had his iconic music-video-esque romantic role (in Baz Luhrmann’s Romeo + Juliet); Efron has his (HSM). DiCaprio broke out of the tween ghetto with Titanic; Efron broke out, to a lesser but still remarkable extent, with last year’s Hairspray (which has grossed close to $200 million worldwide).

Unlike DiCaprio, though, who at the height of his post-Titanic fame was notorious for gallivanting around with his “pussy posse” of bad boys, Efron remains, unwaveringly, Mr. Clean. Since much of the adult audience that knows him by name hasn’t necessarily seen any of his work, his fame can seem two-dimensional: He’s the smiley, androgynous pretty boy in all those High School Musical promo shots, looking so innocent and sun-kissed you could almost mistake him for an animated Disney character.

Which is why the paparazzi have, actually, been accidentally helpful. If there’s one reason Efron has graduated from Popstar! pinup to mass-market cultural phenomenon, it’s surely the shots of him canoodling with his High School Musical costar Vanessa Hudgens during a Hawaiian getaway last year. Those pictures, he says, were a rather startling wake-up call. Though he’d previously been “papped,” mostly at official HSM and Hairspray events, the “Zanessa” pictures were stealthily shot on a beach via telephoto lens. “At that point it was inconceivable,” he says. “I had no idea that anyone could ever care. That happens to, like, big stars. I woke up and my dad told me that I was in a newspaper on the beach—he made fun of me, he said I was ‘frollicking.’”