Middle school is, of course, a horror show.

Bad skin. Brain and body growing in weird directions. All those deeply confusing new feelings.

And in the midst of this — your most terrifying and vulnerable moment — you’re thrust into the thunderdome, where a status-obsessed pecking order (and your place in it) has already been firmly established.

You’re now intelligent enough to articulate your misery, but not yet wise enough to fully comprehend it, let alone rise above it. Some part of you knows this won’t last forever. But it feels like it will.

“Eighth Grade,” the remarkable debut feature from writer/director Bo Burnham, gets at this feeling with more truth and humor and humanity than any movie I can think of.

Burnham ventured into the dark heart of modern-day middle school and returned with a brutally accurate and unflinching film, one that feels both absurdly funny and heartbreaking in hindsight. Just like middle school itself.

Front and center of nearly every shot in “Eighth Grade” is a brilliant young actress named Elsie Fisher. She plays Kayla, an introverted teen trying to endure her last week of eighth grade.

Kayla isn’t bullied so much as ignored. She was voted “Most Quiet” by her classmates, but she does, in fact, have a lot to say. She posts motivational videos on her YouTube channel, with advice about being yourself and stepping out of your comfort zone. In the videos, she displays a confidence that is almost entirely absent at school.

Her only friend is her sweet-natured single father, Mark (Josh Hamilton). He attempts to break through to her, but he can’t even get her to stop looking at her phone during dinner.

Kayla goes through the motions of her day, trying to survive her last week of middle school and enduring a procession of minor humiliations that you might find amusing or harrowing or both, depending on your grade-school experience.

She has a crush on a dumb boy. She gets invited to the pool party of a popular girl named Kennedy (at the behest of Kennedy’s mother). She digs up, then burns a shoebox time capsule she made in sixth grade, addressed to “the Coolest Girl in the World.”

Inside the time capsule is a SpongeBob SquarePants thumb drive that contains a video addressed to her future eighth-grade self — the video a monument to how thoroughly she’s failed to become the person she’d hoped by now to be.

If “Eighth Grade” is a great movie about adolescence, it’s also a great one about the almost boring ubiquity of technology. Kayla is immersed in screens and apps. There are full sequences of Kayla just sitting in her bedroom, endlessly scrolling through Instagram — liking her classmates’ posts and participating in a community that has barred her from entry IRL. A shattered iPhone screen becomes a symbol of her spiraling mental state.

In an earlier version of the script, Burnham was woefully dated on his social media. (He had the kids using Facebook!)

But he invited Fisher and the rest of his young cast to be story collaborators, and they educated their ancient director (27!) on how young people live online in 2018. This collaboration carries through every frame of “Eighth Grade,” every line of dialogue. It’s rare to find a movie that rings this true, especially when it’s about something as alien as modern teenagers.

“Eighth Grade” is part of a renaissance of great teen movies (like “Lady Bird” and “The Edge of Seventeen”) about young women trying to make it through the meat grinder of adolescence intact. But whereas those movies still have the veneer of movieness to them, “Eighth Grade” often feels like a documentary.

It’s not that Burnham’s filmmaking lacks for oomph. He lands a few killer track drops, and he ensconces the visuals in an appropriately Internet-y aesthetic. But his script and Fisher’s performance don’t have an ounce of artifice on them.

Kayla feels so real — is so easy to empathize with — that by the time the big emotional scenes come around, the movie doesn’t need to do much or say much to leave you devastated. In the end, this is a profoundly eloquent movie about a young woman struggling to express herself — refusing to be consumed by the horrors of youth.

There’s no small amount of hope at the heart of “Eighth Grade.” Hope that it will get better for Kayla. Better for anyone. But the movie also understands something essential, something from which it derives much of its power:

It understands that whatever happens after, your time as a frightened, awkward kid will echo on down throughout the rest of your life. That what you like to think of as your adult personality is really just a compilation of defense mechanisms you picked up in middle school.

A note on this movie’s R rating

The film contains some bad language and sexual content. There’s a scene in which a character looks up a how-to-give-oral-sex tutorial video on YouTube and considers practicing on a banana. At one point, there’s a threat of sexual assault. There’s also a disturbing and darkly funny scene in which Kayla and her classmates do a school-shooting drill.

Despite this, or perhaps because of it, I’d recommend taking older children to “Eighth Grade,” if you think they’re mature enough to handle it. There’s no other movie right now that so earnestly attempts to understand what it’s like to be a teen.