In “Sly,” director Thom Zimny captures a side of Sylvester Stallone seldom seen. The 95-minute docu exposes a relatable, vulnerable man who is often thought to be the movie characters he made iconic — Rocky Balboa or John Rambo.

Born in 1946, Stallone grew up in New York City’s Hell’s Kitchen with little money and a father who might have hated him. Zimny’s docu reveals that the fraught upbringing turned out to work in Stallone’s favor when it came to Hollywood. The star’s background not only drove him to be a success, but also inspired many of the roles he made legendary.

Unlike many celebrity docus, “Sly” isn’t a valentine to the star as much as a retrospective of the Oscar-winner’s unlikely, but highly successful 50-year career.

Variety spoke to Zimny ahead of the Netflix premiere of “Sly” on Nov. 3.

I’m sure many filmmakers...