“Faster alone, further together,” Brad Pitt murmured. Over his left shoulder hung Mars, reddish-brown and heartbreakingly small, while to his right, the much grander Jupiter was lit up like a disco ball.

We were seated opposite each other on the lowest level of the Griffith Observatory in Los Angeles, inhabiting a closed-off exhibition called “Depths of Space,” mulling stoic men. Pitt has played his fair share of them in the movies, including two characters just this year: Cliff Booth, the bemused stunt man who sauntered through the summer hit Once Upon a Time … in Hollywood, and Roy McBride, an astronaut shuttled to lonelier, ever more remote outposts of the galaxy in the coming Ad Astra.

Movie stars have their specialties, and while Pitt has proved that he can play a motormouth in films like 12 Monkeys and Snatch, he’s at his most alluring when he’s holding something in reserve. It feels like you’re watching a man who says no more than he needs to, which is a major feat for someone who has starred in two films from the notoriously loquacious Quentin Tarantino.

“I grew up with that be-capable, be-strong, don’t-show-weakness thing,” Pitt told me. He was raised in Springfield, Missouri, the eldest of three children, his father the owner of a trucking company. Now, at 55, he’s reached a point where he sees his dad in every performance he gives. “In some ways, I’m copying him,” Pitt said. “He had grown up in extreme hardship and poverty, always dead set on giving me a better life than he had — and he did it. But he came from that stoic ilk.”

That lineage has served Pitt better onscreen than off, and in a year in which he has delivered two major performances, he’s giving hard thought to the person he’s become. “I’m grateful that there was such an emphasis on being capable and doing things on your own with humility, but what’s lacking about that is taking inventory of yourself,” he said, hunching over in his chair. “It’s almost a denial of this other part of you that is weak and goes through self-doubts, even though those are human things we all experience. Certainly, it’s my belief that you can’t really know yourself until you identify and accept those things.”

Hours later, long after we had spoken, the texts started to pour in from friends and family: What was Brad Pitt like, and how did he look? For most of our conversation, Pitt was both penitent and private, as though he were toggling between the person giving confession and the priest receiving it. As for what he looked like: Well, he was wearing a gray newsboy cap, gray T-shirt, and gray hair on his chin. Some surprising tattoos snaked down his arms, including a Rumi quote, a motorbike, the word “Invictus,” and a man and his shadow. Mostly, though, he looked just like Brad Pitt.

I didn’t have to ask James Gray whether he wrote Ad Astra with his star in mind; when I watched the film, I knew as soon as the other characters began marveling that Pitt’s astronaut has a pulse rate that never goes above 80 beats per minute. Gray likes to tell a story that illustrates Pitt’s even keel, and it’s a tale that fills in a few gaps if you’ve ever wondered why Brad Pitt wasn’t present when Moonlight, a movie he executive-produced, won best picture at the Oscars two years ago.

As it happens, Pitt was indeed in Los Angeles that night, but he had skipped the festivities to go to a spaghetti dinner at Gray’s house, a surprising display of priorities for someone with Hollywood’s highest accolade on the line. While Pitt, Gray and a few other friends ate dinner, Gray’s wife holed up in another room to watch the Academy Awards, and Pitt had to find out secondhand that his film was involved in one of the wildest Oscar moments ever: when La La Land was mistakenly announced as best picture and the real winner was Moonlight.

And how did Pitt react when he was told what happened? Gray affected Pitt’s unruffled drawl — “He said, ‘Oh wow, that’s cool’” — and laughed at the memory. “He wasn’t unappreciative, obviously, but Brad won’t get caught up in pomp and circumstance. I think he knows to stay centered.”

Pitt and Gray have been friends for more than two decades, ever since the actor saw the director’s 1995 debut, a low-budget crime drama called Little Odessa. At the time, Pitt was swerving away from the long haired hunks he’d played in Legends of the Fall and Interview With the Vampire, and he felt that Gray could coax something new out of him. “He had this ’70s touch, like the films I was weaned on,” Pitt told me. “There was a roughness to him, a violence. And he seemed to be focused on men.”

Gray was startled when Pitt reached out. “It’s not easy to imagine a person who is beginning to enter peak stardom calling me up when I was 25 years old and hadn’t done anything except for this movie,” Gray said. “It was bizarre, surreal. But I was very touched. He has very artful taste, and he’s always seeking out new points of view.”

The two men were determined to collaborate, but there were false starts. In 2010, Pitt dropped out of Gray’s jungle epic, The Lost City of Z (the part ultimately went to Charlie Hunnam). “At that time, journeying into the Amazon just did not fit into my schedule,” Pitt said.

Years later, Gray would go to Pitt with Ad Astra, expecting him to turn that down, too. “Even when he said he would do it, I never thought he would do it,” Gray said, explaining, “My only quibble with Brad on a professional level is that he doesn’t star in movies enough. I think he’s able to command the screen in a way very few other people can, and I wish I saw that all the time.”

If Pitt is quieter in person and more thoughtful than you might expect, so is Ad Astra. To be sure, there are some striking action sequences as Pitt’s character combs the galaxy in search of his missing astronaut father (Tommy Lee Jones). But Ad Astra is more concerned with its protagonist’s inner life than the magnificent starscape outside his spacecraft, and long stretches pass with only Pitt onscreen, his voice-over pondering life’s profundities.

“We’re asking questions like, ‘What’s it all about?’ and ‘Why are we here?’ That’s a bit of a minefield, because there are so many traps,” Pitt acknowledged. But the loneliness of the character appealed to him: “We wanted to investigate the inability to connect with others, and the self-protection mechanisms one builds up that keep us from really being open.”

Openness is something Pitt has been thinking about a lot lately. It is a quality that does not always come easily to men, and no one would begrudge the most scrutinized actor in the world if he wanted to seal off parts of himself. “But the ultimate place for my style of acting, as I understand it, is to get to a place of just absolute truth,” Pitt said. “I’ve got to be experiencing something that’s real to me for it to read real to you.”

In early 2017, when Pitt committed to starring in Ad Astra, he was still reeling from his recent split from Angelina Jolie, with whom he has six children. “He definitely used the stimuli from his life,” Gray said. “Now, I didn’t get personal with him about it at all — I don’t think it’s my business, or even my job — but he investigated the essence of the character through himself.”

When I asked Pitt about that period of time in his life, he at first curtailed the inquiry. “I had family stuff going on,” he said. “We’ll leave it at that.”

Was Ad Astra a way to work through some of the loneliness he may have been experiencing? “The fact is, we all carry pain, grief and loss,” he said. “We spend most of our time hiding it, but it’s there, it’s in you. So you open up those boxes.”

It was reported that the final straw in Pitt’s 11-year relationship with Jolie came in September 2016, when they fought about his drinking while aboard a private plane. Now, Pitt is committed to his sobriety. “I had taken things as far as I could take it, so I removed my drinking privileges,” he told me. After she filed for divorce, Pitt spent a year and a half in Alcoholics Anonymous.

His recovery group was composed entirely of men, and Pitt was moved by their vulnerability. “You had all these men sitting around being open and honest in a way I have never heard,” Pitt said. “It was this safe space where there was little judgment, and therefore little judgment of yourself.”

Astonishingly, no one from the group sold Pitt’s stories to the tabloids. The men trusted one another, and in that trust, he found catharsis. “It was actually really freeing just to expose the ugly sides of yourself,” he said. “There’s great value in that.”

In August, BUZZFEED published an article titled “Brad Pitt Is a Character Actor Trapped In a Movie Star’s Body.” In it, writer Alison Willmore argued that Pitt was at his best when cast as a slightly subservient co-lead — as in “Fight Club,” where he plays Edward Norton’s alter ego, or “Once Upon a Time … in Hollywood,” where he lends Leonardo DiCaprio a shoulder to lean on. The latter role will probably earn Pitt his fourth Oscar nomination for acting, and “the contradiction of his three-decade career,” Willmore said, “is that his best roles are almost entirely supporting ones.”

According to Gray, Pitt’s ego has little to do with choosing a part. “He’s always advocating for less exposition and fewer lines,” Gray said. “I don’t think Brad necessarily likes being the center of attention — he has to be shoved in that direction.”

To hear Pitt tell it, at least those supporting roles offer some sort of reprieve: He’s been the center of the world’s attention since his 1991 breakout role in Thelma & Louise, so why would he always need that in his work?

“In the ’90s, all that attention really threw me,” Pitt said. “It was really uncomfortable for me, the cacophony of expectations and judgments. I really became a bit of a hermit and just bonged myself into oblivion.”

Everything he did then was scrutinized: His hits, his misses, his hair, his body and especially his romances — among them, an engagement to Gwyneth Paltrow and marriage to Jennifer Aniston. His life, he told me, wasn’t simply “the lottery it appeared from the outside.” It got to the point that he could no longer tell his own feelings and wants apart from the ones impressed upon him by others.

Eventually, as Pitt graduated from male-ingenue roles and forged a rewarding partnership with director David Fincher, with whom he has made Seven, Fight Club and The Curious Case of Benjamin Button, Pitt began to find his footing. And though his union with Jolie made him even more cataclysmically famous, by then he’d at least learned to shrug off everyone else’s expectations.

“Those dubious thoughts, the mind chatter, the rat in the skull — that’s comedy,” Pitt said. “It’s just ridiculous that we would beat ourselves up that way. It doesn’t matter. I spent too much of life wrestling with those thoughts, or being tethered to those thoughts, or caged by those thoughts.”

Pitt recently called acting “a younger man’s game,” and in his mid-50s, he has found himself increasingly drawn to other artistic pursuits. He is prolific as a producer — “Producing just means you don’t have to get up really early and put on makeup,” Pitt told me — and Plan B, the production company he runs with Dede Gardner and Jeremy Kleiner, has backed films like 12 Years a Slave, If Beale Street Could Talk and Selma.

Still, he’s not especially bullish on the future of big-screen entertainment in the streaming era: “I’m curious to see if movies last, if movies stick around,” he said. What he does know is that he won’t be starring in as many. “It’ll be fewer and farther in between for me, just because I have other things I want to do now,” said Pitt, whose interests include sculpting and landscaping. “When you feel like you’ve finally got your arms around something, then it’s time to go get your arms around something else.”

With that, our interview was done, and we ascended two staircases, emerging from the depths of space onto the lawn of the observatory. It was crowded with tourists, most snapping pictures of the Hollywood sign just across the canyon. Pitt would have to cross through the sprawl to get to his waiting car, and he asked me to stay back: If I walked alongside him, treating him like a famous person, then the people here would realize he was one.

So I stayed behind as Brad Pitt strode off by himself, walking past throngs of tourists who stared at the sign instead of the Hollywood star unknowingly in their midst, a man with all the fame in the world but no real desire for it, a man who was faster alone.