Audiences may think they knowSylvester Stallone, but an intimate new documentary is sure to prove otherwise.

“There were tons of moments in our interviews where things he shared with me were just never talked about or shared in print or the research that I did,” Zimny tells PEOPLE of filming with Stallone. “I would have these sessions with him where we would talk for four to five hours.”

From the moment he met Stallone, Zimny adds, “I knew that I was not going to work in a traditional talking head format because he has too much energy. I wanted to film him standing up and put him in his office, where I met him the first time, and let him have free reign, really no restrictions.”

Slyintermixes footage of those no-holds-barred conversations in his Los Angeles home with photos from his childhood, behind-the-scenes footage of his pre-Rockyfilmmaking efforts and scenes from the many hit movies that followed. Stallone speaks plainly about navigating the Hollywood spotlight and even listens to his old press interviews, mocking and yelling at his younger self.

Sylvester Stallone in “Sly”.Courtesy of Netflix

Sylvester Stallone in Sly

Courtesy of Netflix

“He’s done a lot of work on himself in understanding who he is as an artist and a family man,” says Zimny. “From the experience of being around the household and getting a sense of their home while filming, the filmmaker in me recognized that he had great love for his family and great love for his wife,” he adds ofJennifer Flavin, who’s been married to Stallone since 1997 and sharesdaughtersSophia, 27, Sistine, 25, and Scarlet, 21, with him.

“But the core of his discussions I saw again and again,” says the director, “is a desire to create.” While many associate Stallone with onscreen stardom with theRocky,RamboandExpendablesfilm franchises, Zimny says what struck him most filmingSlywas “the hundreds and hundreds of notebooks that he had.”

“You flip through those notebooks, and you see the dedication that he had in refining and editing. That was the biggest surprise, that this whole side of him was not really honored in some ways.”

Sylvester Stallone in Sly

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A quote from Stallone in one of their hours-long conversations helped Zimny connectSly’s thematic dots: “When you’re first born, you’re like soft clay, and the impressions that the world can give you sometimes can leave a mark… I realized that this would be a key part of the film, to unpack childhood and how that has made us.”

Stallone, he says, has spent his life “writing about a universe and a world that he didn’t experience as a child.”

“Much like the Rocky character, he was not understood in the world,” adds Zimny. “He had the power of the pen to create a universe that would not only change his life but inspire generations.”

source: people.com