What is it like to be an Oscar winner — and a mere mortal — at the exclusive Vanity Fair Oscar party? Let’s walk in behind Brie Larson and find out. (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

Shhhhh, Jennifer Garner is approaching and we mustn’t look too eager, mustn’t look needy, must ever so casually scooch over on the leather bench to show that there’s room here if she wants to sit — those strappy heels look so uncomfy, Jen — and finally, all at once, we’ve done it. Vanity Fair magazine’s current cover star folds up her ball gown and plops down next to us.

She smells like cucumbers, and America.

To the right: Whoopi Goldberg in high-top sneakers. To the left: Faye Dunaway in a formidable pantsuit.

The Oscars ceremony might be one of the most prestigious events in the celebrity world, but the Vanity Fair celebration is the most exclusive after-party — a celebrity State of the Union in which all of the movie stars in all of the land are brought to one large building to hobnob and glad-hand and get away from the mortals.

Whoopi Goldberg arrives at the Vanity Fair party. (Evan Agostini/Invision/Associated Press)

Eddie Redmayne, right, with wife Hannah Bagshawe. That’s a very touchable-looking tux you’re wearing. (Evan Agostini/Invision/Associated Press)

It’s harder to get into than the White House (electronic key cards must be presented at two checkpoints), and it’s more expensive to get into than college (invited A-listers pay nothing, of course, but wannabe arrivistes have been known to bid $200,000 for a pair of tickets at charity auctions), and the world inside the Wallis Annenberg Center for the Performing Arts is one where the ratios are all wrong: Every person there is famous.

Inside is the demystification of celebrity. Inside is the anthropological exercise of our times.

Rooney Mara! Hello, and you are eating french fries and your dress looks much less doily-ish in person. Jason Bateman! Hello, and you have a very large head. Near a cluster of high-top tables, Paula Patton, a.k.a. Robin Thicke’s ex, brushes against the shoulder of Emily Ratajkowski, a.k.a. Robin Thicke’s mostly naked music video muse. They do not appear to notice each other but — hand to heart — as they pass, the faraway DJ cues up “Blurred Lines.” Patton rolls her eyes. Just think how many times she’s heard this song, how many times she must’ve tried to explain that “hug me” didn’t rhyme with the words Thicke thought they rhymed with.

Paula Patton, you must be so sick of hearing that one song. (Danny Moloshok/Reuters)

Let’s take a lap through astronomical fame, shall we? Weaving through the white-jacketed servers and comfy leather sofas and dance music, and . . .

Dear God, is that Mickey Rooney? Quick Google. No, Mickey Rooney died in 2014. Who is it? Who is the adorable raisin sitting on the squashy chair surrounded by more fans than anyone else in the room?

Ed Asner?

Alan Arkin?

No. No.

Mustn’t stare at the old man. Must stare instead at Eddie Redmayne, chatting with Captain America Chris Evans. They are intently stroking each other’s tuxes. Eddie’s looks like it is made of velvet, and he is saying “Shut up! Shut uppp!” but in a delightful British way. Must stare instead at Adrien Brody, with some sort of Frenchy silk scarf wrapped around his neck as he periodically claps along to Michael Jackson, or at best-actor nominee Bryan Cranston, who is explaining, “It’s satin,” as someone else fingers his jacket sleeve. Rampant tux-stroking — is this a thing?

Chris Evans, right, with siblings Scott and Carly. (Evan Agostini/Invision/Associated Press)

It’s great, Jon Hamm. It’s great! (Pascal Le Segretain/Getty Images)

Must fight through the hipster-eyeglassed cadre of screenwriters to get outside for a breath of air, because that’s where the cigarette smoking is happening, and that’s where host Graydon Carter is shaking hands, and so that’s where we expect the fun, naughty people to be.

“It’s great! It’s great,” Jon Hamm is reassuring someone out on the patio. Then that person walks away and Hamm turns to comic Louis C.K. and says, “That’s all actors ever need to hear: ‘It’s great, it’s great.’ ”

“Hey, has anyone watched ‘Vinyl?’ ” someone else asks Hamm and C.K. and another friend in the group.

A long pause.

“It’s not great,” one of them responds.

C.K. leaves the patio and meanders back into the main room, where he gets down on one knee in front of the pruny non-Mickey Rooney man, in some sort of deeply respectful homage. Who is this?

Desperate Google search: “Old white bald famous comedians.”

Don Rickles! Don Rickles is the pruny comedian to whom all other comedians must pay their respects! Glad that’s settled.

Sylvester Stallone arrives without an Oscar but with his wife, Jennifer Flavin. (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

Ohhh, the first big Oscar winner has arrived. Brie Larson, changed out of her blue ceremony gown into something pink and slouchy. She slowly makes her way through the herd of photographers outside and then — let’s follow as she enters the door, shall we? What does it feel like to be an Oscar winner entering this party?

Answer: It feels like a big hug from Common, the first guest to spot Larson when she steps inside.

“Wonderful,” he tells her as she throws her arms around his neck. And then — please let us through, Daisy Ridley, pardon us, Sissy Spacek — we’ll follow Larson toward the bar, where another guy keeps bellowing at her — “I always said you were the real thing!” — while she orders a drink, and then we’ll follow her . . .

Well, we won’t be following her anywhere, because suddenly the path is blocked by “Spotlight”: Michael Keaton and Liev Schreiber and Rachel McAdams and a bunch of producer-types with a bunch of Oscar statuettes. Pardon us, fellas, but — but no, we are stuck, we are packed too tightly between the butts of Keaton and Jake Gyllenhaal, who has nothing to do with “Spotlight” but has suddenly appeared and is immovable.

Oscars host Chris Rock with his mother, Rosalie Rock, left, and actress Megalyn Echikunwoke. (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

“I just saw her last night,” Keaton says to his friend.

“Just keep your head above water,” Gyllenhaal says to his own friend.

Keaton: “She was my date.”

Gyllenhaal: “Just keep your head above water.”

This is it. This is how it ends. Until the end of time, trapped between a former Batman and Maggie’s brother, forever and ever and . . .

“Is that Gaga?” someone shouts. “It’s Gaga!”

Just like that, the crowd loosens, lubricated by the desire for Lady Gaga, as people whip out their iPhones and surge toward the corner where Gaga graciously poses for selfies — selfies with Gwen Stefani, selfies with Taylor Swift visible in the background, and, while we debate our own desire for a selfie, we find that Jason Segel, most recently of the David Foster Wallace biopic “The End of the Tour,” is standing on our dress.

“David Foster Wallace was a family friend,” we tell Segel. (True.) “Dad said you really captured Dave’s spirit.” (No clue whether Dad ever saw the movie.)

“That means so much,” Segel says, putting his hand over his heart, looking genuinely touched. “That really means so much.”

It’s great, it’s great. We’re getting the hang of this.

Alicia Vikander has a moment with her Oscar. (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

Mark Rylance introduces his Oscar to the party. (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

“How many burgers have I had?” demands a deeply concerned Seth MacFarlane at the In -N-Out stand outside. The counter lady holds up three fingers. “Three? I’ve had three burgers?”

“We could say it’s two if that would make you feel better,” she says, handing him another one.

“So this would make three?”

“If you want it to be.”

“Just tell me,” he begs. “Tell me how many burgers I’ve eaten.”

Oh, dear. Ben Affleck has arrived, and, after maintaining an appropriate quarantine in the outdoor-smoking portion of the party, he begins to migrate toward the leather-sofa portion of the party, where Jennifer Garner still mingles. Just two days earlier, she had broken her silence about their divorce in a soul-baring interview published by Vanity Fair; now we are watching them move toward each other as if watching a slow-motion collision.

Uh oh, there’s Ben Affleck. Is this going to be awkward? (Adrian Sanchez-Gonzalez/Agence France-Presse/Getty Images)

His ex, Jennifer Garner. Everything’s totally civilized here. (Danny Moloshok/Reuters)

But then it’s fine, it’s totally fine. They greet each other warmly and linger near each other at close proximity; it’s all very friendly and grown-up and — this is hard to explain — but the weird, complicated humanity of it makes us feel that we belong here at this party for the absurdly rich and famous. We are all just people, after all. This all makes sense.

Then a starlet approaches, the name escapes us, but young and fresh-faced, the kind you’d see in a Disney musical, and she greets us a bright smile.

“You look just like Emma,” she purrs, tracing a line in the air around our face.

Oh really? Emma Watson? Emma Stone? Emma Thompson? All Emmas are good Emmas.

“Emma,” she starts again. “My publicist’s dog-walker.”

Right, then.

The Don Rickles chair has been taken over by Quincy Jones, himself now attended by a long line of young Hollywood people waiting to pay respects. Leonardo DiCaprio and Alicia Vikander have come and gone. Actually, a lot of people have gone. The tables are littered with empty champagne flutes, the floor is littered with crumbs.

“See you at the next party?” a woman calls to her friend.

“This is the last party,” the friend cackles back. “The only party.”

The stars of the world, and their publicists and dog-walkers, all head out into the Hollywood night.