Sylvester Stallone on the fight to make "Rocky"

Long before he became the most famous cinematic fighter of all time, Sylvester Stallone had to fight his own battle to survive in New York. For example, he was living in places where he literally had pizza boxes for his mattress. "I did, yeah. It was very comfortable," he said.

His jobs also included cleaning the lion cages in the Central Park Zoo. "That's a rough one, because I felt so bad for these magnificent animals," he said, "and then I felt bad because I smelled like them, you know, going home."

As a starving actor in the big city, life was tough, but his upbringing wasn't much easier. Born in New York's Hell's Kitchen 80 years ago, Stallone says his parents sent him away to a boarding house at a very young age. He says he understood. "I almost didn't blame them," he said. "I was very rambunctious."

His parents were not the kind to show affection. "No. I don't think they knew how. There was zero touching," he said.

No hugs? "Oh, no, no, no."

But Stallone says his hard-knocks childhood was great training for the uphill battle he'd face trying to make the passion project of his life. His struggle was so epic, they've made a film about it: "I Play Rocky," coming out this November, about how Stallone kept the faith when the only thing he kept hearing was "No." Stallone wasn't involved in making the movie, but he says they really nailed it.

Asked how he was able to keep going as doors kept getting slammed in his face, he replied, "Because I consider there's a process of elimination. Eventually they're going to open the door."

He wound up making his own door. In a story that's now become legend, Stallone wrote the script for "Rocky," with himself in mind for the title role.

He wrote it in about 3½ days, and credits divine intervention: "I said, 'Is this Your plan to, like, torture me? To this-and-that to test me? All right, I've come this far, I refuse to break.' And I went back in and I finished the last few pages of 'Rocky.' I really felt as though something guided my hand, because I've never been able to do it since. So, that's why I have to give credence to some sort of divine guidance."

Stallone finished the "Rocky" script in March 1975, but the starving actor was now just a starving screenwriter; he was still flat broke. He ended up selling his dog because he couldn't afford to feed him. "It's the only thing I could sell. It was like, that was it," he said.

In his new memoir, "The Steps" (to be published Sept. 29 by William Morrow), Stallone recounts how producers offered him thousands for his script, but only if they could cast someone else as Rocky Balboa. The bidding went as high as $360,000. "I said, pass. I can't do it," he said. "I've literally crawled through every gutter in New York. I've slept in every alleyway. I have paid my dues, and I know this is it. I will never have this opportunity again. I don't know if you believe in destiny, but I think in some cases, it happens."

The film went on to become a cultural phenomenon, with three Oscars (including best picture) and monster box office. As Rocky, Stallone was unstoppable. He'd even bought back his dog, named Butkus, and put him in the movie.

Stallone went on to star in another franchise, Rambo. But in the 1990s, that star began to dim. He said, "When you artistically die and nobody wants you, where do you go? You're just like the 10th wheel going to parties, but you're not relevant. You're not missed."

He said that happened to him for about six years when he was artistically dead. Asked how he resurrected himself, he replied, "The pen!"

Ah yes, the pen. In 2006, Stallone wrote a sixth Rocky script, and directed the film himself. It was a good move: "Rocky Balboa" was a box office and critical smash, and put Stallone right back on top of the list of Hollywood heavyweights, most often playing the guy who beats the odds and somehow comes out on top.

It seems he's done that in his career, too; Stallone has starred in at least one #1 box office film in each of the past six decades. The only other actor who can say that is Harrison Ford.

And talk about crazy movie accolades: the film about him, "I Play Rocky," is very much in this year's Oscar conversation. 

Stallone's also taken his talents to streaming TV. Next month he'll be in his fourth season of the series "Tulsa King" on Paramount+ (owned by the parent company of CBS). He sometimes shares the screen with Scarlett Stallone, one of three daughters he has with his third wife, model Jennifer Flavin, to whom he's been married for close to 30 years, despite a few bumps along the way.

Asked what he's learned about marriage in that time, Stallone replied, "What have I learned from her? That I'll never be as good as her. She's just magnificent, has kept me alive. And it took me so long to turn my head around and go, 'Oh, you have the greatest gift in the world right here and you're looking out there, you fool!'

Stallone met us at New York's Carbone Restaurant (he's a friend of the family there). It's a far cry from the New York he knew in the 1970s when things were bleak, but the world was his for the taking.

"It isn't as though I have a love affair with New York," he said. "New York to me was a battlefield, and it still is, you know what I mean? It's beautiful, the shops and the culture, but I walk these streets, I would look at the cracks, I could see the filth and whatever. And so, I always approached it as this, I kind of like descend into a hell, you know? Like, are you going to be able to elevate yourself from this to some penthouse someday? You know what I mean?"

And he did it. "Look at me now!" he laughed.

READ AN EXCERPT: "The Steps" by Sylvester Stallone

WEB EXCLUSIVE: Watch an extended interview with Sylvester Stallone (Video)

For more info:

• "The Steps: A Memoir" by Sylvester Stallone (William Morrow), in Hardcover, Large Print Trade paperback, eBook and Audio formats, available Sept. 29 via Amazon, Barnes & Noble and Bookshop.org
• "I Play Rocky" opens in theaters Nov. 19
• Thanks to Carbone Restaurant, New York City