With acclaim raining down, Casey Affleck tries to enjoy it

NEW YORK — After spending the night shooting the most devastating scene in “Manchester by the Sea” — a scene in which, Casey Affleck’s character, clutching a bag of groceries, stands before a tragedy that haunts him throughout the film — Affleck tripped and felt a shooting pain run up his back.

Writer-director Kenneth Lonergan, a veteran back-thrower, quickly yelled for Affleck to move around to keep the muscles from seizing up.

“He’s like, ‘Get up! Pretend you’re throwing me a ball!’ ” Affleck recalled.

So there, beneath the early morning winter light, in an empty parking lot, ran Affleck and Lonergan in helter-skelter patterns, playing an imaginary game of catch. It was a rare moment of lightness shared between two self-acknowledged grouches, and a brief reprieve from the grief-filled seas of “Manchester.”

But both, and particularly Affleck, have had plenty reason to celebrate lately. Affleck’s natural, heavily burdened performance in “Manchester by the Sea” has been perhaps the most universally acclaimed of the year.

He’s already won best actor from the Gotham Independent Film Awards, the National Board of Review and the New York Film Critics Circle, and he’s widely viewed as the Academy Award favorite.

It’s unquestionably a high point for Affleck, who, unaccompanied, met a reporter earlier this fall at Manhattan’s Carlyle Hotel. But far from doing cartwheels, Affleck is mostly mystified why films like “Manchester by the Sea” are so hard to come by.

“This is what it’s about. It’s just awful how rarely it happens,” said Affleck. “I tend to focus on the negative, I confess. But I do keep thinking: Should I just pack it in? Is it really every 10 years that you get to work on a great movie? That can’t be.”

Such self-deprecation, bordering on self-loathing, is not the kind of thing you often to hear from Hollywood actors on the Oscar trail. Affleck has been here once before, with his Oscar-nominated performance in 2007’s “The Assassination of Jesse James by the Coward Robert Ford.”

That’s one of the films he cherishes, along with the lyrical 2013 outlaw romance “Ain’t Them Bodies Saints.”

But that’s about it.

“I have to live with that r?sum? that you see on IMDB which is full of dog s—,” said Affleck. Building concrete steps in Cambridge as a teen, he said, gave him more tangible satisfaction.

The 41-year-old actor is known for such hand-wringing. Matt Damon, a longtime friend and “Good Will Hunting” co-star, recalls hourslong phone conversations with Affleck, wrestling over which job to take.

“It’s literally like talking to Hamlet,” said Damon.

Earlier versions of “Manchester by the Sea” famously had Damon directing or starring. But a commitment on “The Martian” forced him to hand the role to Affleck, who had starred in a London production of Lonergan’s “This is Our Youth.”

“Ben (Affleck) and I have been convinced for the last 18 years that next year is going to be the year for Casey,” said Damon. “But there wasn’t anything he passed where you could go back and finger-wag him and say, ‘You really should have done that.’ He’s just got really high standards. He’s very pure creatively until he runs out of money, like any of us, and he has to do whatever he has to do because he’s got kids.”

Parenthood figures prominently in “Manchester by the Sea,” in which Affleck, a janitor in Boston, is given guardianship of his late brother’s teenage son (Lucas Hedges). Affleck, himself, has two children, who visited once during the Massachusetts shoot.

In March, Affleck and his wife, Summer Phoenix, announced they had separated.

While Affleck has a number of acting roles lined up, he’s preparing to direct again, this time a father-daughter survival tale called “Light of My Life.” He notes with typical worry that it will take him away from acting for a year. But anxiety, he says, comes with the territory.

“If it’s your job to go to work every day and be authentically depressed, you put yourself through things,” he said. “It’s not surprising that you don’t find a steady, even-keeled contentment in life.”

Normally, he can’t even bear to watch himself in a film.

“But I watched this,” Affleck said of “Manchester.” “And I liked it.”