'Arnold' doc: Schwarzenegger was 'emotionally spent' talking about affair; Maria Shriver declined to participate, director says

You might think you already know everything about Arnold Schwarzenegger: He's the greatest bodybuilder ever, putting the obscure sport on the map. He's been the biggest box office star in the world, conquering action and comedy. And who can forget the Terminator star's stint as Governor of California? Then there are those private transgressions, like his affair while married to Maria Shriver.

So, when Lesley Chilcott was approached to direct Netflix's new Arnold documentary, she first wondered: "What's not to know? It's all been out there, right?"

But Chilcott tells Yahoo Entertainment that Schwarzenegger's "absolutely bizarre trajectory" was too "intriguing" to pass up.

"There's all of his successes, but there's a lot of personal failures," she explains. "As a filmmaker, for me, he's complex, and he has layers and I felt like the public doesn't know as much about his layers, and that made it a challenge."

Schwarzenegger discusses several of those personal failures in the final episode of the three-part series. After all, Chilcott says, "part of the deal" in making this with the actor was that "no topic is off the table."

"He agreed," she confirms, "and he went there."

One of the painful topics he discusses is the affair. In 2011, Schwarzenegger and Shriver, his wife of 25 years, announced their separation as he confirmed he fathered a child, Joseph Baena, with their housekeeper in 1997. Schwarzenegger publicly apologized to Shriver and their four children: Katherine, Christina, Patrick and Christopher.

"It's difficult for him to talk about the affair because he cannot talk about it without someone's feelings getting hurt. That was a pretty grave transgression," Chilcott notes. "And he has to be careful, because he has a human life out of it, a great 25 year old kid [Joseph]. So there is only so much you can say."

Schwarzenegger reveals in the documentary that he told a "crushed" Shriver the truth about his infidelity and love child during a counseling session. Their therapist asked him a very specific question at Shriver's direction. ("I thought my heart stopped," the actor admits. "And then I told the truth.")

"[Arnold] tells us how sorry he is and that the reason he doesn't talk about it is because it hurts everyone... Joseph's family, Maria, all the kids, and he doesn't enjoy that," Chilcott says. "He knew he had to [talk about the affair], but after we talked about it, there wasn't much else we could do that day. He was emotionally spent, and I don't believe he intends to talk about this subject anymore."

Joseph is featured in the documentary, and has developed a close bond with his dad in recent years. But neither Shriver nor the four children she and Schwarzenegger share participated in Arnold. Chilcott says she spoke with Shriver while making the docuseries.

"We did talk, we talked a few times," she explains. Chilcott confirms she asked Shriver to participate and that she "politely declined."

As for where Schwarzenegger and Shriver's relationship stands today, Chilcott says the action star still loves his ex-wife.

"They are all in touch regularly and they're all friends. I mean, they spend a good portion of their life together and they still do family events together and they're very close," she adds. "You know, they can't be together, but they're very close and they're very friendly."

Aside from the affair, the other topic Chilcott says Schwarzenegger had a hard time discussing was his dad, Gustav, who served in the Nazi party during World War II. In Arnold, Schwarzenegger says his father was an abusive "tyrant" at times.

"He had a hard time talking about his father without justifying his father's behavior," Chilcott recalls. "Austria was on the losing side of the war, and by fighting in the war, [Gustav] is by definition is a Nazi, right?"

Chilcott says Schwarzenegger "grew up in a town full of broken men" and many men "were abused as kids." That's, in part, how Schwarzenegger tried to justify what he went through.

"Men of that generation, they set goals, they don't go to therapy... So, Arnold's instinct is to not reflect on it. And he would be... because I asked him and he would go there, but then a few minutes later it's like, 'Oh yeah, but the neighbor was also getting abused...' to try and justify it. So, it's difficult for him to talk about his father."

However, Schwarzenegger credits his tough Austrian upbringing for helping him succeed.

"He always says, 'through my Austrian sense of discipline and American opportunity, I was able to do so much.' I mean, I have never met anyone who truly believes in the American dream more than him," Chilcott shares. The award-winning filmmaker hopes that's something that sticks with people who watch Arnold.

"I think it's a really simple lesson, but every once in a while you, we need to see a story where someone just believed so much that they could succeed, that they did. That there's a little piece of that American dream that might still be possible," Chilcott explains.

"You know, when we filmed in Arnold's old house in Austria, it's a museum. There were young men coming in from countries all over... some had tears in their eyes. Arnold was [a man who came] from a humble beginnings. As wildly successful as he is, people see his success as an achievable one. It's different than a Nobel Prize winner," she laughs, "but with Arnold, somehow people identify with him. It gives them hope, and as flawed as he is as a character — and he is flawed — it's nice to see that after all these years, he's not jaded and he still believes the dream."

Chilcott believes that Schwarzenegger, who turns 76 next month, is "satisfied with big parts of his life."

"He looks back at everything and he thinks he could have done everything better. I think that's natural," she explains.

"I think he's really proud of all of his kids, you know? And he's really proud of all of the friendships that he's had for decades," she explains. "He's satisfied with many things, but he wants to do new things."

Catch Arnold on Netflix, out now.