Stephen Chboksy has found the secret to eternal youth. Write an age-defining cult novel to capture your emotional life and experiences -- then immortalize it on film. Chbosky, author of beloved adolescent angst tome "The Perks of Being a Wallflower," accomplished just that.

Over the last 13 years, the writer's had plenty of opportunities to sell the film rights to his coming of age story. But, Chbosky couldn't fathom passing over the reins for a big-screen adaptation, in part because he drew upon his own life for his main character's journey, and also thanks to rabid reception the novel received from fans.

"I always wanted to make the movie," says 42-year-old Chbosky, "But over the years, with the fan response to the book, that lifelong dream became an obligation."

Chbosky struck young adult lit gold in 1999 with his spin on the coming-of-age archetype. The story -- presented in the form of letters written to a stranger by shy high school freshman Charlie -- delves into the psyche and relationships of teenagers, making it a sort of "Catcher in the Rye"-esque calling card for Millennials. As Charlie seeks out acceptance, love and friendship, Chbosky brutally encapsulates the crippling anxieties and towering triumphs of young adulthood.

Published by MTV Books, Chbosky's novel has sold more than a million copies, and along the way repeatedly earned a place on the American Library Association's list of "10 Most Frequently Challenged Books" for its explicit, honest portrayals of teenage sex and sexuality, and substance use.

"You don't sell your babies for money," he says. "Back when I was 29, and I had no money, and they offer you the six-figure deal to write the screenplay and [sell] the book rights; yes, it was tempting. But in that moment, I remember thinking, that if they offered me $10 million, I would have said no. That's when I knew someday I would do it myself."

So Chbosky kept the rights. Today, 13 years after the novel's release, his film is finally out.

"For me, it took this long [because] I just needed the distance. It's so personal to me," says Chbosky. "I needed that time to not be so precious about it. I had to do a real adaptation and not just try to film the book."

"The Perks of Being a Wallflower" has some dark, even devastating moments -- the sort of tropes only gleaned from real life experience. And that's no mistake. Chbosky's story is semi-autobiographical, it's set, and filmed in his real-life hometown of Pittsburgh, Pennsylvania.

"I shot in my hometown. And to be able to go to the theater where I first saw 'Rocky Horror Picture Show,' or there's a little scene on Christmas Eve where the aunt is talking to little Charlie, and if you turn the camera slightly to the left, that's my house. And my parents got $1,500 of location fees and they're so happy," said Chbosky with a laugh.

"When I was making the movie, my secret hope was that I'd make a movie that would make people not feel alone, whether there was, like, a teenage kid or their parents, that they would feel validated and respected for what they go through."

Chbosky was happy to get "Harry Potter" star Emma Watson in a lead role, along with rising stars Ezra Miller and Logan Lerman, who plays Charlie.

"He was the second person to audition for Charlie," Chbosky said. "And after Logan's reading, there was no need for anybody else, you know? Within five seconds, you just know."

If a writer directing his own film sounds off, it's actually far less odd than you might think. Chbosky is no stranger movies. He studied screenwriting at University of Southern California, was mentored "Rebel Without A Cause" screenwriter Stewart Stern, and went on to write the screenplay for the film adaptation of "Rent," as well as write and executive-produce the TV show "Jericho."

"The Perks of Being a Wallflower" has generated some strong audience support.

"It's really strange that you can point to a moment in your life and think, 'My life will never be the same,'" he said. "But it's when we got a standing ovation from 1,200 people at the Toronto Film Festival. From that moment on, suddenly, like, two days later on Monday, 'Hey, Steve, you want to look at this book?' 'Oh sure, okay.' And then, here we go."

"The Perks of Being a Wallflower" also features Paul Rudd, Dylan McDermott, Mae Whitman, Nina Dobrev, and Kate Walsh, and is in theaters now.

Chbosky is currently working on a new novel he hopes to eventually turn into a film.