No one likes eighth grade. It’s the compulsory military service of American adolescence, the cod liver oil every child must swallow on her way to adulthood. In the rigged Russian roulette game of human genetics, it’s the bullet in the chamber, that pimple-infested, body-odorous, hair-in-uncomfortable-new-places minimum-security prison every girl must endure, the real-life horror movie to which you can’t close your eyes. Worst of all, the scars that happen here are pretty much guaranteed to haunt you for life.

Welcome to “Eighth Grade,” kids! Whether it’s been two days or two decades since you suffered through it yourself, your heart goes out to Kayla (Elsie Fisher), the young woman we meet tightrope-walking over those shark-infested waters in writer-director Bo Burnham’s remarkable feature debut. If Burnham’s name doesn’t ring a bell, then you most likely belong to the demographic who will see this movie as a cross between last year’s “Lady Bird” (also produced by Scott Rudin) and Larry Clark’s ultra-cautionary “Kids,” identifying with Kayla’s dad (Josh Hamilton, rivaling Michael Stuhlbarg in “Call Me by Your Name” for World’s Greatest Dad) as his daughter narrowly avoids (or not) the landmines upon which you’d gladly throw yourself in her place.

Like a taller and less-tattooed version of Justin Bieber, Burnham began his career on YouTube in late 2006 with an original song called “My Whole Family Thinks I’m Gay.” He was 16 at the time, three years older than Kayla’s character, and somehow managed to leverage his viral-video success into a comedy songwriting career, turning his quick-witted insights into piercingly funny, unapologetically irreverent rap songs. Apart from a handful of lo-fi music videos Burnham has made over the years, there was nothing to suggest that he had it in him to direct a film, which makes “Eighth Grade” one of the sweetest surprises of this year’s Sundance.

Bead-braided, 10-rated ’70s sex symbols aside, Bo is a boy’s name, of course, which makes this gender-flipped act of adolescent empathy all the more remarkable. Every year, Sundance is littered with deeply narcissistic, transparently autobiographical coming-of-age stories. As Hollywood lawyer Linda Lichter so aptly put it Peter Biskind’s “Down and Dirty Pictures”: “At Sundance, the bulk of the pictures are about losing your virginity. It’s babies making movies about babies. With some exceptions, the filmmakers don’t really have a voice yet.”

Burnham is that exception. An accomplished comedian, Burnham has already put in his 10,000 hours, honing what he has to say for nearly a dozen years, and as such, “Eighth Grade” shines as, like, a totally spot-on, you know, portrait of Millennial angst and stuff. That may be how Kayla (and all her peers) talk, punctuating their quasi-articulate ideas with hesitant “ums” and “ahs,” but Burnham shows a sociolinguist’s ear for the cadence and flow of 21st-century girl-speak, and Fisher (who dubbed adorable young Agnes in all three “Despicable Me” movies, but will almost certainly be new to audiences) delivers his dialogue so naturally, you’d swear she’s making it up as she goes along.

Using the three-beep countdown of the PhotoBooth app as a kind of audio motif throughout, the film opens with Kayla recording a motivational YouTube video hardly anyone will watch. “The hard part of being yourself is that it’s not easy,” she stammers into her laptop camera, imploring people to “like” what she has to say, and signing off with a cutesy “Gucci!” catchphrase. When I was Kayla’s age, I poured most of my free time into publishing a newspaper nobody read. Today, kids (technically “teens,” since 13 is the first of those gloriously awkward years) chase YouTube and Instagram validation instead.

“Nobody uses Facebook anymore,” quips Kayla’s prettier, more popular classmate Kennedy (Catherine Oliviere), whose birthday party falls just a few days shy of both girls’ middle-school graduation. “So my mom said to invite you, so this is me doing that,” writes Kennedy — voted “best eyes” by her classmates, though how could they have noticed, when her eyes are constantly glued to her smartphone? Kayla is equally obsessed with her devices, and the movie pretty much nails it when she gets up one morning, does her makeup, and then crawls back in to bed to take her first Snapchat selfie of the day.

“Eighth Grade” unfolds over those final days of that ignominious year, during which Kayla coaches her nonexistent YouTube subscribers on such skills as confidence and “putting yourself out there,” while wrestling to put her own advice into practice. At Kennedy’s party, she retreats to an empty room and plays with her phone, cutting her finger on her shattered iPhone screen — an ingenious visual metaphor for everything her generation is dealing with these days, and yet, wonderfully understated at the same time. Burnham doesn’t feel the need to veer off into ultra-dark Harmony Korine territory, an envelope that films such as Fien Troch’s “Home” and Catherine Hardwicke’s “Thirteen” have pushed clear off the table in recent years.

Though so much of “Eighth Grade” feels achingly honest, Burnham can’t help but fall back on a few of the stock coming-of-age-movie clichés: Kayla’s obsessed with a classmate named Aiden (Luke Prael), for whom the soundtrack swells and the world moves in slow-motion every time he appears, and she barely notices Gabe (Jake Ryan), the weird kid who wants more than naked selfies or a quick trip to third base from her. Like Dawn Wiener in Todd Solondz’s infinitely harsher “Welcome to the Dollhouse,” Kayla wants the validation of a cute guy’s attention. But it’s not like she’s going to marry either of these boys anyway.

Fisher has the unique challenge of making an average girl seem exceptional, tapping into that universally identifiable sense of vulnerability that shows plain as acne at that age. Somehow, Kayla escapes without a single person asking what she wants to be when she grows up (although an early montage shows her doodling googly-eyed anime characters into her spiral notebook and showing a certain aptitude in art class), and that’s one stress she can defer to next year, when she hits ninth grade. Middle school, as Burnham shows it, has changed a lot since most of us were there: Where previous generations learned to duck-and-cover in the event of a Russia-launched nuclear attack, these kids roll their eyes during a school-shooting drill.

Consider this: Neither Kayla nor Kennedy had been born yet when the movie “Mean Girls” was released, and they’re both entirely too self-absorbed to be proactively cruel to their classmates anyway. “Eighth Grade” isn’t about bullying; it’s about how hard we are on ourselves at that age. At one point, Kayla opens a shoebox time capsule she addressed “to the coolest girl in the world” two years earlier, and seems not to recognize the girl whose hopes and dreams it contains. It’s too bad she can’t send a message in the opposite direction, reassuring her insecure younger self that “It Gets Better.”

Film Review: ‘Eighth Grade’

Reviewed at Sundance Film Festival (competing), Jan. 19, 2018. Running time: 93 MIN.

  • Production: An A24 release. Producers: Scott Rudin, Eli Bush, Lila Yacoub, Christopher Storer.
  • Crew: Director, writer: Bo Burnham. Camera (color): Andrew Wehde. Editor: Jennifer Lilly. Music: Anna Meredith.
  • With: , Daniel Zolghadri, Fred Hechinger, Imani Lewis, Luke Prael, Catherine Oliviere. Elsie Fisher, Josh Hamilton, Emily Robinson, Jake Ryan