Stars, we’re told, are just like us, but the annual Costume Institute Gala is pretty solid evidence that’s not quite true.

One after another, they exit their big black Escalades and ascend the stairs of the Metropolitan Museum of Art in their skyscraper-high Louboutin heels and diaphanous custom-made gowns, to hobnob with the fellow members of their rarified species, whose resplendent outfits they admire and whose cheeks they plant kisses on as the photographers go snap, snap, snap.

Later in the evening, they’ll sip on Veuve Clicquot, admire Lady Gaga’s bravura performance of “Bad Romance,” and hoof it a few blocks over to a super duper exclusive afterparty at the Mark Hotel.

Click the Image to View Our Gallery of the Metropolitan Museum's Costume Institute Gala

But now, it’s just beginning.

And begin it does with the arrival of none other than Anna Wintour, the editor in chief of Vogue, and the lady behind the whole event.

There she is with her perfect bob haircut and her perfect Chanel gown, along with her two perfect-looking children and a phalanx of perfect-looking people following in hot pursuit.

“What are you wearing, Bee?” the reporters yell to the editor’s daughter as mom gamely talks to a camera crew somewhere in the distance.

“Balenciaga,” she says, while striking a pose, or two, or three.

We try to get Wintour’s attention, but it’s no go.

No matter. There’s enough movie stars and fashion royals coming to this affair to rival the Oscars.

Someone in the A-plus crowd—Karl Lagerfeld, Jennifer Lopez, Carolina Herrera, Hugh Jackman, Calvin Klein, Tina Fey, Donna Karan, Anne Hathaway, Diane von Furstenberg, Blake Lively, Nicolas Ghesquiere, Diane Kruger—will talk to us.

Why, look! It’s Nicole Richie, who has arrived in a totally perfect glittery Marc Jacobs dress, and who is chatting it up with Donatella Versace.

Since the theme of the exhibition is American women, we ask the Italian style maven a silly question about what she likes about American women, and she says, “American women are a little bit safer than European women, but they’re very themselves.”

We’re trying to figure out if this is really a compliment, when another reporter interrupts.

What American woman would she most like to dress?

“Michelle Obama,” Versace says. “She has such great style.”

Suddenly, the photographers are going insane. Oprah Winfrey is here. And not just Oprah, mind you, but Oprah flanked by the dapper-as-ever Oscar de la Renta.

Reporters descend.

“He’s the quintessential American designer,” Winfrey says of her date, as a throng listens with rapt attention. “Years ago, when I thought I might actually be the marrying kind, I dreamt of getting married in an Oscar de la Renta gown. I truly feel like Cinderella at the ball.”

Was she at all intimidated by the prospect of going to work on the event with a woman who’s occasionally been known to inspire fear as much as admiration?

“She called me directly and you go ‘eeggghhh’ it’s Anna Wintour,” says Winfrey, giving a look of mock worry. “It’s been great.”

Soon after, guests begin arriving in droves.

There’s Sarah Jessica Parker looking luminescent in a dress for Halston that she designed herself. (In case you haven’t heard, the Sex and the City star is now helping to oversee the 21st-century revision of the fabled fashion brand.)

A hop, skip, and a jump away, it’s Gwen Stefani primping and posing with her husband Gavin Rossdale, in a shimmering off-white frock of her own design. (This is something of a trend at the Costume Institute Gala and at public appearances all over the two major coasts these days. Now that celebrities have their own fashion lines, they no longer need designers to construct their gowns. Or at least, Parker and Stefani don’t.)

Over there on a landing near the top are Justin Timberlake and Jessica Biel exchanging pleasantries with Bono and his wife Ali Hewson (even she has a clothing line).

A few dozen feet away, at the entranceway separating yours truly from the gliteratti cavorting inside, a style summit is taking place, as the legendary fashion critic Suzy Menkes pops photos of herself with Tom Ford and his boyfriend Richard Buckley on what looks like a disposable camera. Ralph Lauren mingles nearby in a tuxedo-jacket, bowtie and faded blue jeans with his wife, Ricky.

Up walks Gisele Bündchen, who’s sauntering by in an Alexander Wang dominatrix-ey black leather thing with slits down the front.

Motherhood has seemingly had no effect on her body, whatsoever.

In fact, the way she tells it, everything about having a child has been a breeze. “He’s the most quiet, easy, peaceful baby,” she says of her four-and-a-half month old son to a reporter from Allure magazine, as her husband Tom Brady walks inside. “People are like ‘Where did he come from. I say ‘I have no idea.’”

Historically, one of the best things about the Costume Institute Gala is that it’s one of the few red-carpet affairs at which people still take some risks.

This year is no different. As Zac Posen puts it, “This is about fashion for fashion’s sake. It holds the bar for the fantasy of red-carpet dressing. It’s dressing for fashion, not for your next role.”

In addition to Lauren’s gloriously mismatched tux and Bündchen’s much-admired ode to S&M chic, Twilight’s Kristen Stewart arrives wearing a black strapless, asymmetrical dress cut up to there with a sheer overlay and enough black eyeliner to rival Siouxsie Sioux during her “Cities in Dust” phase.

Renée Zellweger strolls over a few minutes later, in a Carolina Herrera mermaid dress that’s got a black and gold Jackson Pollock-like splash effect, and says there’s no doubt she feels freer here to go all out than she does at other red-carpet affairs.

“It’s like, ‘If not now, when?’” Zellweger says, around the time Marc Jacobs makes his way up the steps in a baseball cap, explaining to Women’s Wear Daily the real reason for his odd sartorial choice. “I had a hair transplant.”

But the evening’s winner for most daring celebrity is clearly pop singer Katy Perry, who shows up in a gown that lights up like a billboard in Times Square. “I chose it because fashion can be really serious and I want to lighten things up,” she says.

Plus: Check out more of the latest entertainment, fashion, and culture coverage on Sexy Beast—photos, videos, features, and Tweets.

Jacob Bernstein is a senior reporter at The Daily Beast. Previously, he was a features writer at WWD and W Magazine. He has also written for New York magazine, Paper, and The Huffington Post.