More actors than ever are now stepping behind the camera to take a shot at directing. To me, they always end up falling into one of three categories. There are the ones who simply aren’t very good at it. There are the ones who wind up making a movie that’s A-okay (not better, not worse), often because they’re more attuned to the nuances of guiding their fellow actors than they are to the grander artistic machinery of filmmaking. And then there’s the elite third category: those rare actors — Greta Gerwig, Ben Affleck, Bradley Cooper — who turn out to be born filmmakers.

To that hallowed company we can now add the name Jesse Eisenberg. “A Real Pain,” which he wrote, directed, and co-stars in, premiered yesterday at Sundance, and it’s a delight and a revelation — a deft, funny, heady, beautifully staged ramble of a road movie about two Jewish cousins, David and Benji Kaplan (played by Eisenberg and Kieran Culkin), who are taking what someone calls a group “Holocaust tour” of Poland. The tour traces the odyssey of Jews over the last century or so, centering on the historic cataclysm of World War II. David and Benji also plan to seek out the home that their grandmother, who died just a few months before (she was a Holocaust survivor), grew up in.

“A Real Pain” is full of blustery talk about a great many things, and the suffering embedded in Jewish history — the way the past speaks to the present ­— is one of them. But only one. David, the straight arrow of the two, is played by Eisenberg in a baseball cap as a vintage Jesse character — earnest and uptight, with a compressed delivery that expresses his nervous nature, yet this is no millennial Woody Allen caricature. Emotionally, David is a bit of a lox, but he has it together. He lives in New York City with his wife and adorable tyke of a son, and he works selling digital banner ads, a responsible and colorless job that suits him. It was his idea to take a week off to do this trip, which he’s arranged and paid for, mostly so he can spend some quality time with Benji (Culkin), the cousin he grew up with and was close to (their fathers were brothers), though the two have drifted apart.

That can happen, even with relatives you cherish, though in the case of these two youthful 40ish men, it’s a temperament thing. David is a sweet but conventional middle-class drone, whereas Benji is a loose cannon — a bro who never grew up, the kind of dude who says “fuck” every fifth word, who advance-mails a parcel of weed to his hotel in Poland, and who has no filter when it comes to his thoughts and feelings. He’ll blare it all right out there. Since he’s a brilliant and funny guy who sees more than a lot of other people do, and processes it about 10 times as fast, he can (sort of) get away with the running monologue of hair-trigger nihilist superiority that’s his form of interaction. He can also be quite nice, and knows how to play people. Yet he is, at heart, an anti-social misfit, one who’s clinging to the recklessness of youth just at the moment he should be leaving it behind.

The two are thrown in with the half a dozen other members of the tour group, all of whom are middle aged or older and quite serious about what they’re doing. This makes Benji the antic bomb-thrower and wild card, which is his comfort zone. He jokes and jabbers and interrupts and says inappropriate bro-y things. Yet he’s charismatic. People are drawn to the wit of his self-centered energy. (That’s why he’s spent his life getting away with it.) The film presents Benji as a version of the Magical Pest character — the one played by Bill Murray in “What About Bob?,” Owen Wilson in “You, Me and Dupree,” and Adam Sandler in “That’s My Boy,” the hellacious man-child the world should shun, only he turns out to be the life of the party.

Yet Culkin, for all his crack timing, is not giving a “comedy” performance. He’s doing a sensational piece of acting as a compulsive wiseacre addicted to the ways of one-upmanship. Benji has the personality of a hipster slacker crossed with that of a corporate dick. He’s funny, he’s rude, he’s charming, he’s manipulative, and he will suck the life out of you. Yet Culkin makes him real, and the movie, which Eisenberg has scripted with an ear for the music of ideas and for contrasting voices, presents the story of these two cousins — how they interact, what they mean to each other, how their past intersects with the present — in a way that’s so supple you can touch their reality. To put it as Benji might: This, people, is what fucking filmmaking is about.

At first, Benji seems irreverent about history itself. Journeying out from their hotel in Warsaw, the group stops at a WWII memorial for Polish soldiers (who loom, in sculpted metal, 15 feet tall), and all Benji wants to do is pose next to the sculpture and have his photo snapped; David thinks that’s disrespectful, but everyone in the group soon poses along with him.

Things turn more somber when they hop a silver train into the Polish countryside. They all have first-class tickets, and Benji starts ranting about how offensive this is given what trains meant to Jews during the Holocaust. He can be a kind of left-wing scold, but what he’s saying here might almost be a page out of Milan Kundera. He’s moralistic, but he’s right, and the fast-talking action begins to sink into a meditation on our relationship to the past. At the site of Poland’s oldest gravestone, Benji chews out the tour guide (Will Sharpe, from “White Lotus”), a British chap who is not Jewish, for pelting them all with too many facts. He’s right about that one, too.

The film’s title, of course, is a pun. Culkin’s Benji is obnoxious enough to be “a real pain,” but the movie is also about what it takes, in a world conspiring to insulate us from reality and history, for people to experience real pain. Eisenberg unfolds the story with an organic flow, and he has a gift for interweaving airy comedy and gravitas — the unbearable lightness of good screenwriting — that’s reminiscent of what Richard Linklater brought off in the “Before” films. “A Real Pain” is an easy watch, a buddy movie rooted in the existential fun of verbal sparring. Yet it has an emotional kick that sneaks up on you. The other actors all make their marks — Jennifer Grey as a perky but mournful newly divorced Los Angeles “lady who lunches,” Daniel Oreskes and Liza Sadovy as a stolid bourgeois couple, Kurt Egyiawan as a survivor of the Rwandan genocide who converted to Judaism. By the time they journey to the Majdanek concentration camp, the film opens itself up to sorrow and pity.

Benji, the most arrested person on hand but also the most thoughtful, keeps insisting on the primacy of history. The complex way the movie views him is that his perception gives him soul, even as he’s unable to apply it to his own life. He’s brilliant but lost, unlike David, who has found himself. I never saw Eisenberg’s first feature as a director, “When You Finish Saving the World” (which played at Sundance in 2022), but I can testify, or at least predict, that he’s going to have a major filmmaking career. As for Kieran Culkin, his performance in “A Real Pain” feels karmically timed to the end of “Succession.” He was just crowned with an Emmy, but he started off in movies, playing the hero of the superb “Igby Goes Down” when he was 19, and “A Real Pain” establishes that his fast-break insolence can work on the big screen in a huge way. The film’s final shot is a beauty, because the entire question raised by Culkin’s Benji — can he change and redeem himself? — is reflected, with haunting ambiguity, in his look. That’s stardom.