'Rebel in the Rye': A rarely seen side of 'Catcher in the Rye' author J.D. Salinger

— -- J.D. Salinger’s controversial novel, “The Catcher in the Rye,” is considered by many to be an American masterpiece.

Yet the man behind the tale is still a fascinating enigma, even though he essentially disappeared from public view after the book’s release in 1951. To date, it has sold over 65 million copies.

Salinger’s formative years are explored in a new biopic about his writing career and perseverance after World War II called “Rebel in the Rye,” in theaters now.

Danny Strong, an actor, writer and co-creator of the hit TV series “Empire” makes his directorial debut with this film. He said that in writing the screenplay, he learned surprising revelations about his subject.

“I didn't know that he had gone to war,” Strong said. “I didn't know about his religious awakening and I didn't even know he was this charismatic young man of New York City who had transformed because of the war experience.”

The film chronicles Salinger’s struggle with PTSD after the war -- he was an army sergeant and was part of the U.S. forces that stormed the beaches of Normandy in 1944 -- which led him to discover meditation.

“I knew nothing about … [Salinger’s] landing on D-Day … the results of that [are his] coming back, finding the Vedanta Hindu religion,” said actor Nicholas Hoult, who plays Salinger in the film. “He was very ahead of his time.”

“It's that meditation, that peacefulness -- because he did suffer a lot of PTSD, and in that era, it wasn't as recognized or understood,” Hoult continued. “That was a huge part of him being able to write again, and also just trying to find peace from all the horrors he saw and more.”

Both Strong and Hoult practice meditation and yoga themselves. In putting this movie together, Strong said his own meditation practice helps him feel “more creative and more focused.”

In his daughter’s 2000 memoir, “Dream Catcher,” Margaret Salinger writes that her famously reclusive father would jump to different religions.

“When I see that, I see someone trying to find some sort of peace or trying to heal themselves in some way,” Strong said. “I see a racing mind that is looking for some sort of answer.”

Hoult, whose breakthrough role was at age 12 in the film, “About a Boy,” plays the tortured writer and said in researching the role, the most inspiring thing that stuck out to him was Salinger’s devotion to writing and “his willingness to write as a meditation and for not for the rewards of what you might receive from it.”

Salinger’s creation, Holden Caulfield, would go on to become one of the most iconic characters in literary history. But the intense public scrutiny brought on by the success of “Catcher in the Rye” pushed Salinger further into a reclusive state.

“I think to be able to walk away when you reached success like that is extremely bold and noble thing to do in many ways,” Hoult said.

While Strong believes Salinger would have never approved of the unauthorized biopic, he does believe the troubled writer’s life is fascinating. Salinger was 91 when died in 2010 at his home in New Hampshire.

“I never would have done it if he was alive because I think it would have been very emotionally painful for him,” Strong said. “His life is worthy to be explored but more importantly, I think that what he went through, having gone through the war and then coming out of the war and creating a masterpiece after suffering the horrors of that experience, is a really inspiring story.”

Listen to the full interview with actor Nicholas Hoult and writer/director Danny Strong on the "10% Happier" podcast on Apple Podcasts, Spotify, Google Play Music, Stitcher, TuneIn, on ABC Radio podcasts and under the "Listen" tab on the ABC News app.