In a particularly wrenching scene in “The Father,” a new film directed by the French novelist Florian Zeller, Anthony Hopkins’s title character is disoriented with dementia, talking to a caregiver. He asks when his mother is going to visit him and begins to cry, repeatedly saying: “I want my mummy. I want my mummy.”

“Just saying those words takes me back to the age of 4 or 5,” Hopkins said on a recent Zoom call from California. “Grief of a child, you know. They’re left outside of the shop, and they get scared. So that’s all in there. It’s all contained in the back of my head.”

There are many similarities between Hopkins and his latest tour-de-force, Golden Globe-nominated role. Hopkins turned 83 on Dec. 31. His character in “The Father,” also named Anthony, has the actor’s exact birth date. His character’s flat is decorated with paintings and a piano — Hopkins himself is a painter and pianist — and even the character’s wardrobe reflects the actor’s sartorial preferences.

“He always likes [a] cardigan,” said Debra Winger, Hopkins’s co-star in the 1993 drama “Shadowlands.” “Yeah, there’s so much Tony in there.”

Hopkins has quipped that he “didn’t have to act old age, because I am old.” And while neither of his late parents experienced dementia, he remembered his father raging against the dying of the light when the old Welshman’s fatal heart disease left him angry and confused.

“I started doing [the film], and I didn’t think of it,” said Hopkins. “But when I saw it later, I thought I was my own father.”

If you follow Sir Anthony Hopkins on Instagram, though, what you’ll see is the playfulness and mischievousness of a little boy. There he is playing piano with his cat, Niblo, on his lap. There he is contorting his face and cackling maniacally, starting to feel the “side effects” of quarantine.

That persona may be jarring to fans of the veteran thespian who, in his Oscar-nominated roles in films such as “The Remains of the Day,” is the very master of dignity. But his friend and frequent acting partner, Emma Thompson, knows that kind of behavior to be the real “Tony.”

“There’s a kind of Welsh sprite in there, a Celtic spirit,” said Thompson, who first worked with Hopkins on the period drama “Howard’s End” in 1992. It was right after he won his first (and only) Academy Award for playing cannibal Hannibal Lecter in “The Silence of the Lambs.” They met in an elevator, and Thompson handed Hopkins a note from her mother — the Scottish actress Phyllida Law, who knew Hopkins — that read: “Hello Tony. I hope you’re well. This is my daughter. Please don’t eat her.”

“He just laughed,” said Thompson. “But I remember those extraordinary eyes, and that coiled energy. I thought, ‘Oh god, I’m going to have such a good time with this person.’ Because he was so funny . . . And also clearly anarchic, as well as a volcano.”

Hopkins grew up in a southern coastal town in Wales as the only child of Richard and Muriel, a couple who led a hardscrabble life running a bakery. His grandfather toiled in the steelworks, “and I remember him coming home from work exhausted,” said Hopkins, “his boots white with sweat and salt, working in the blast furnaces. Anyone who complains to me about anything, I say, ‘You know nothing. Wake up, smell the coffee, because you know nothing.’ ” It’s an attitude the multi-award-winning actor still has today as he constantly deflates his profession of self-importance and emphasizes the ease of his work: “It’s common sense. There’s no big deal to it.”

Hopkins found that calling early, and within a decade of graduating from college he was understudying for Laurence Olivier at London’s National Theatre. He made his international debut acting opposite Peter O’Toole and Katharine Hepburn in the Oscar-winning 1968 film “The Lion in Winter” and never looked back.

Hopkins was “a bit of a bad boy” when he was starting out — he recently celebrated his 45th year of sobriety — but despite his own volcanic energy and humor, he has often been cast as the butler or the buttoned-up patrician. He supposes it’s because Americans just perceive British people that way. But aloofness also does come naturally. Ever since his childhood he’s felt like an outsider. Working alongside such acting royalty as Judi Dench at the National Theatre, it was “no one’s fault,” he said, “but I didn’t feel I could fit in. I never have, all my life. I guess I’m slightly paranoid.”

But that paranoia hasn’t translated into a lack of self-esteem in his craft. “When you go into the arena, you have to be really confident,” Hopkins said. “You can’t wing it. I know actors that like to listen to [their lines] through an earphone. That, to me, is anathema. So by the time, having learned the sheer text of [the script], and the rhythms of it, I’m confident going on set. I have no doubts at all. And that was after years of experience, of working with some great actors like Olivier, and Peter O’Toole — [who] was a wild man, but when he was on set in ‘Lion in Winter,’ he knew every syllable.”

His co-stars attribute Hopkins’s easy acting style to his total openness. Olivia Colman, who plays his daughter in “The Father,” said that “of the actors that I really admire, that I’ve been lucky enough to work with, they all have a similar thing — which is sort of no armor at all. Complete honesty. He’s sort of like a great big puppy. He’s willing to play. He’s willing to do anything.”

He’s also one of the great on-screen weepers. At just the right moment in a given story, his stoic composure will begin to crack along with his voice. He has this endearing quirk where he lifts his hand up in a fist and blocks the side of his face as he begins to cry.

It’s something he learned a long time ago, and he relates it to the way he played Hannibal, a “monster” masquerading as a dignified gentleman — as the opposite of what the audience expects.

“You’re letting the audience do the work for you,” he said. “In emotional scenes, when you have to break down, if you go the opposite direction of trying to not break down, the tension becomes tough, and the audience will pick up on it. And they’ll do it for you, and then you go.”

“Oh God, he just tore my heart out,” Winger said after watching “The Father.” “All he did was stay open — those beautiful eyes — and he was so relaxed.”

Hopkins remembers one of the only times he saw his own father cry. It was a cold winter night in 1957, and they had just cremated his grandfather. His father, a withholding, “tough old guy,” suggested they get fish and chips on their drive home. They were eating the essential British food out of paper bags when the old man suddenly broke down.

“I had to walk away,” Hopkins said. “I couldn’t bear being near him. I always remember he covered up because he didn’t want to be seen.”

It’s the mother-son relationship, though, that’s reflected in the actor’s new film. Hopkins “just adored his mother,” Winger said. “And I think that came from that same place that, whatever magic and whatever she did right, in a way allowed him to keep the young boy inside of him.”

Muriel Hopkins was widowed in 1981, and she lived with her son (who moved to America in the ’70s) until she died in 2003. “She was a strong, powerful woman,” Hopkins said. “I think she was like all mothers — a bit possessive. I’m the only child. But I’d be abnormal, I would be nothing without that bond or that connection.”

“We can hide behind machismo, machoness, you know,” he said, comically grunting, but being an actor lets loose “all those so-called emotions that I don’t like to display too much. When I’m working as an actor, I have a lot of memories. A lot of things come to the surface from childhood.”

It’s a through line in his work: In “The Lion in Winter,” Hopkins plays a bit of a mama’s boy to Hepburn’s Eleanor of Aquitaine. (At one point, Eleanor calls Prince Richard “unnatural,” and he retorts: “Unnatural, mommy?”) At the end of “Shadowlands,” the widowed author C.S. Lewis is sitting in his attic with Douglas Gresham, the young son of Lewis’s short-lived wife, Joy. Hopkins, as Lewis, tells Douglas that his own mother died when he was a boy, and that he prayed and prayed for God to make her better. “It doesn’t work,” Douglas says. “No,” Lewis replies. “It doesn’t work.”

Oliver Stone cast Hopkins as disgraced president Richard Nixon in his 1995 biopic after seeing him as Lewis; he wanted the actor to bring some of that same human warmth to the great American villain. In the film’s climax, Nixon — who has heretofore taken manly pride in never crying — kneels with Henry Kissinger and prays. Holding his hand against his face to hide from the awkward secretary of state, he begins to sob: “Oh, Mom. I’m sorry.”

Winger marveled at Hopkins’s relationship with his mother, which she witnessed up close during “Shadowlands.” It allowed him to feel “like someone’s boy for a really long time,” she surmised — which is what he accessed in “The Father.” “But,” Winger added, “I just don’t know anyone who doesn’t want their mom when they get sick.”

Hopkins believes we’re all deeply lonely, and acknowledging that, along with our know-nothing state, is liberating. And in yet another trait he shares with his character in “The Father,” Hopkins listens to music to enhance that feeling, particularly arias.

“I think they string into something so deep inside us — the female,” he said. “You hear Maria Callas sing, and you think: Oh God. Goes back to the mother.”