The first time Eighth Grade actress Elsie Fisher saw herself on the big screen was during the films first screening at the Sundance Film Festival on a Friday night. The theater was packed to the rafters, the temperature inside was rising, and all eyes were on the teenager—the first frame of the first scene featured an intense close-up of the bright-eyed blonde with acne-riddled skin and faux confidence making a YouTube video, the self-help kind teenagers today will watch endlessly. That was all Fisher needed to burst into tears.

“Oh yeah, I immediately started crying. Like, immediately,” said Fisher. “As soon as I saw my face. I couldnt handle it, man.”

Fisher isnt the only one. The now 15-year-old is sitting for an interview with her writer-director Bo Burnham in the heady days following that raucous screening. The audience went crazy for the duos collaboration, a poignant, somewhat hilarious, ultimately tragic portrayal of teenage life that is both an examination of how technology is affecting these kids development, and a reminder of the painful rite of passage that is middle school, no matter the era. “I think you got what you wanted,” said Fisher to Burnham. “The audience syncs up their heart rate with Kayla.”

Eighth Grade centers on the last five days of Kayla Days eighth-grade year. What is supposed to be a joyous milestone is filled with big and small humiliations for the awkward teen who isnt overtly bullied but rather ignored, trying desperately to form connections but unable to make a friend. What begins as a hilarious coming-of-age tale, about the specific clumsiness of being 13, turns quickly to despair as the audience realizes the gravity of Kaylas isolation.

“I think the scariest thing nowadays is not being seen,” said Burnham. “I feel with kids—with all of us, really—were very conscious of the movie of our lives. And thats Kaylas struggle. Shes convinced that the movie of her life sucks.”

It makes sense that Burnham, 27, wanted to make a movie about the Internet. Since 2006, the gangly Bostonian has been posting comedy bits and music videos on YouTube, amassing over 200 million views and cementing him at the forefront of a new generation of comics. But Burnham didnt want to write a film that explored the Internet promise of D.I.Y. fame. Instead, he chose to “take inventory” of the disorienting and scary phenomenon of living with the Internet today, not as an adult, but as a teenager whose brain is developing alongside the ubiquitous technology that seems to force young adults into creating online personas before theyve created their actual personalities.

Rather than cram all those thoughts and ideas into a younger version of himself, Burnham chose a teenage girl as his protagonist. That was both a response to the audience hes cultivated during his tours around the country as a stand-up: teenage girls seem to respond best to his whimsical raps, crude poetry, and often personal, poignant stories about his feelings. And the result of his research, when he went online to view the lives of kids today, was that teenage girls made the most sense to him.

“I think my experience as a very low D-, F-level celebrity is probably similar to the experience of being an average 13-year-old girl in the sort of psychic, meta version of yourself that people force on you,” said Burnham, who watched hundreds of videos of teenage boys and girls on the Internet to understand what their lives were like online. “The boys tended to talk about XBox. The girls tended to talk about their souls. If youre going to try and do a story about what it means to be human, boys are just very closed off to even get at those questions. Girls are just a little deeper.”

Yet few are as deep as Fisher, a voice actress (she played Agnes in the first two Despicable Me movies) and soon-to-be high-school sophomore from Thousand Oaks, C.A., who, during the summer after her eighth-grade year, spent 27 days with Burnham in Rockland County, N.Y., imagining the worst possible version of that period of her life. In Eighth Grade, which opens in limited release on Friday, Fishers Kayla is an insecure eighth grader (i.e., every eighth grader) with a penchant for creating online self-help videos while enduring the final, brutal week of a humiliating, isolated middle-school career. An only child to a single dad (Josh Hamilton), Kayla is desperate for connection, finding solace and angst in the vast outlet of the Internet.

“The two craziest times in my life were eighth grade and this very instant. I could barely handle myself then, and I can barely handle myself now,” said Burnham. “I can only imagine going through that right now with these fun, weird, new mediums that are re-wiring us.”

Fisher and Burnham worked closely during rehearsals to ensure the script came more from the head of a 13-year-old girl than a 27-year-old man. “I would always tell her, You know what its like to be a 13-year-old girl right now, and no one else does,” said Burnham, who dissected every line with his lead to guarantee the dialogue rang true. “I didnt want to impose a worldview as a man or as an adult.”

To Fisher, Kayla is not quite her, but a close facsimile. “Were both awkward and stuff, but there are obviously differences,” she said.

Burnham adds, “Elsie has a strength that Kayla maybe has the potential of heading towards at the end of the story. But Kayla could not have been a lead in a film. Kayla could not sit here. I think youre a little lighter. Youre able to brush things off a little easier than she is.”

“Yeah, not completely,” said Fisher. “But I think Im a little more mature-ish than Kayla.”

There is one pivotal scene in the film where Kayla is being peer-pressured by someone she desperately wants the attention of. Her response, which we wont spoil, is both surprising, and heartening, for what it reveals about her character—and about Fisher.

“You dont need a confident personality to say no, and not be peer-pressured,” she said. “Its your decision. I think Kayla can be kind of a role model to people to know that they can say no, no matter if they are quiet in real life, or nerdy or awkward. You cant just be pressured into that. Its not cool.”

Should the movie pop as many expect it to, life is likely to change for both Fisher and Burnham. The actress is still contemplating her future, and in addition to acting, shes also an artist with an interest in applying to the California Institute of the Arts for college.

“This tall man right here is totally a huge influence,” said Fisher, relaying a story about how at the start of her actual eighth grade she had to fill out a questionnaire that included her hobbies and people she admired. “Oh my god, I put Bo down as my hero,” she said with a laugh.

“Not a lot of people know me. Not a lot of kids know me,” said Burnham. “So theres something about that, that we found each other. That we understood each other.”

“There really is a kindred spirit between us,” added Fisher.

“Yeah,” said Burnham. “I think were just, like, wired very, very similarly.”

Said Fisher, “We finish each others . . .”

“Lunches,” said Burnham.

“Exactly,” concluded Fisher.

Get Vanity Fairs HWD NewsletterSign up for essential industry and award news from Hollywood.Nicole SperlingNicole Sperling is a Hollywood Correspondent for Vanity Fair.