Will Ferrell did not have a child graduating from the school. And he is not among the school’s notable alumni, which include broadcaster Barbara Walters, filmmaker Sofia Coppola and New Yorker film critic David Denby. The actor’s presence, as a few resourceful parents learned and his publicist confirmed, was a personal favor to Today host Meredith Vieira, who had a daughter graduating that day.

“You might wonder why I’m doing this,” Mr. Ferrell, dressed in a nondescript gray suit, told the assembly from a podium in the school’s quad. “Well, I was paid $10 million—so this will be the last graduating class!”

Unfortunately, the comedian’s jokes failed to impress an audience that included at least one descendant of gourmet supermarket chain founder Eli Zabar, also an alumnus, and a li’l Lehman Brother. 

Mr. Ferrell called Dr. John Love, the principal of Upper School, the “Love Doctor.” He informed the audience that by the time he graduated high school, the “Corrupt Non-Culture University School,” he had kissed one girl, one time. He suggested that perhaps a member of the graduating class could go on to be the first black president, except that that had already been done.

“He totally missed the punch line!” said Victoria Goldman, author of the perennially popular Manhattan Family Guide to Private Schools, there to support her graduating nephew. “He should have said that someone here will be the first Jewish president! He just fell flat.”

Mr. Ferrell concluded: “Seniors, repeat after me: Dare to dream, dream to dare … love the Kardashians!” And the audience finally surrendered and shook with laughter.

But what is the actual reality?

This year, graduation week began with St. Ann’s, the moneyed-bohemian, touchy-feely, grade-less crown jewel of Brooklyn Heights. Once dominated by the children of artists and writers—alums include designer Zac Posen, gallerist Vito Schnabel (son of Julian), actress Eva Amurri (daughter of Susan Sarandon) and spawn of Sigourney Weaver and Ellen Barkin—the school has in recent years welcomed the children (and money) of investment bankers looking for a little artistic street cred.

Around 7 p.m. on Tuesday, June 9, parents, many in cocktail frocks, filed into St. Ann’s Church on the corner of Montague and Clinton Streets. Their kids wore suits and colorful knee-length dresses instead of caps and gowns. Mini-fans were distributed at the entrance; the old church often gets stuffy.

The St. Ann’s graduating class elects five student speakers, the most memorable of which was a smiley young girl in a floor-length, sleeveless cream gown and weighty diamond earrings named Kimi Lee.

Ms. Lee, whose father teaches print-making at the school, struggled to describe her unique education at St. Ann’s. Maybe it was like a carnival, or maybe …

“It can be an orgy, because, after all, the St. Ann’s ethos has always been uninhibited, experimental, gratifying and incestuous,” she told the audience, before offering that perhaps the best adjective to describe her education was “delicious!”

Another speaker, Sam Sullivan, a student of poetry, said some very romantic things about “enchanted gardens” and “childish frolic” and the importance of “fantasy!”

“Before anyone in the so-called real world has a chance to fool us, the gardeners, the graduates, into believing that our lives are about power or money or anything else equally mind-numbing,” he warned, “let us go out and just be, because only good can come from that. In the real real world, there is nothing, but love.”

Mr. Sullivan then pulled out a guitar and led those gathered in a swaying, earnest rendition of ABBA’s Dancing Queen. 

Later that evening, the students would be headed to a rented after-party in a loft—the secret address was texted to graduates around 11 p.m.—where they would celebrate their commencement with ironic beer like Miller High Life and Busch; sweaty grinding; and privately hired security guards. The after-after-party was at Dumbo Park, where the graduates traditionally watch the sunrise.

At 10 a.m. the next morning, there was a power trifecta of graduations.

At the West End Collegiate Church, mothers with carefully hair-sprayed up-dos and tweed designer suits swooned over their sweet boys with neatly combed hair and gentlemanly loafers, a surprising number of which spoke with British accents. In the audience, The Observer spotted the actor Hugh Grant, wearing a brown blazer and slacks, smirking as the Collegiate boys made their way inside. (Among the graduating class was a James Murray Fitzgerald Grant—presumably a relation.)

Before the director of the Museum of Modern Art, Dr. Glenn Lowry—whose son Nicholas graduated in 2000—delivered the commencement address, a tall, skinny, student-elected speaker named James Englander Underberg got up and referenced some raucous party behavior.

“In second grade, we learned the proper way to show respect for someone’s home,” he said. “For example, how to christen a host’s elevator by breaking a bottle and running away or help bleach a guest’s rug.”

Outside after the ceremony, some of the boys lit stogies. “I was born to hold a cigar!” a young man with freckles named David Rattner was overheard to brag. This summer, Mr. Rattner, who lives on the Upper West Side and is headed to Brown in the fall, will work for Mr. Bloomberg’s reelection campaign. “I have some plans for the future, but I’m allowing myself some freedom,” he said, adding that he has watched Gossip Girl, but found it a bit hollow. “It is a hyperbolic representation of my life,” he said.

“I wasn’t invited here today because I have some gifted capacity to deliver a message of inspiration for the future, no,” declared Ms. Washington, her hair pulled tightly back, dressed in a blue-and-white skirt suit. “You’ve invited me here because I am one of you—a Spence girl, through and through.”

Ms. Washington continued: “Your love and support for one another has gotten you worried a little about leaving here. You love Spence. And you are not sure what to expect. To that I will say, ‘Good, you should be a little nervous, because ladies, the world is not exactly like Spence.’” (Here the parents began to chuckle.)

“Make Ms. Spence proud!” later enjoined Bodie Brizendine, head of school.

Up at the Riverdale campus of Horace Mann, whose class of nearly 200 was four times most of the others, the red, gold, and white Chanel purses were in full bloom.

Upper East Side parent Debra Jaliman, “a Fifth Avenue dermatologist,” said her daughter was headed to the University of Pennsylvania. “It was her first choice; she got in early decision,” Dr. Jaliman bragged. “She worked so hard at Horace Mann and her dreams came true! It’s hard to get A’s here, so if you get the A’s, you’re going to get into an Ivy League school.”

A gentleman in a navy power suit and loafers was not so forthcoming, though he did allow that his second child was graduating from the school. “Horace Mann has been in the public eye a lot lately in a negative light,” he apologized.

Indeed, given New York parents’ traditional guardedness, it’s surprising that NYC Prep materialized at all.

But then again, it is co-produced by the formidable Liz Alderman, who attended the Brearley school for girls (considered the best in its class; as the saying goes: “Chapin girls sleep with the doctors, Spence girls marry the doctors, and Brearley girls become the doctors”) and then returned to teach at the school after Harvard. Another producer, Matt O’Brian, attended Stuyvesant.

“We’re just native New Yorkers that wanted to bring a fresh, East Coast perspective to the teen docu-soap genre and show the rest of America how New York kids operate,” Ms. Alderman said. “These kids have more opportunity than almost any other place on the planet.”

Ms. Goldman, the guidebook writer, expressed skepticism about the show. “Nightingale is the top school in the group!” she said disdainfully. “Anyone going to the top 10 or 15 schools would be smart enough not to be a part of this.”

Ms. Alderman was responsible for easing the concerns of interested parents, who would have to sign off on their children’s participation. Most of them asked her, “If this were your child, would you let them do it?”

“My answer was always, ‘Yes, of course.’ Reality TV is now a fundamental part our collective culture and the TV landscape,” said Ms. Alderman. “It’s a genre that is not going to go away. … Take the reins and make this genre your own.”

The schools that participated did not allow filming inside their walls, and their names are not mentioned. But according to a few speculative online parents’ forums, the brash Peter “PC” Peterson has already graduated from Dwight, where another cast member, Jessie Leavitt, 17, is a senior; the pretty Kelli Tomashoff, 17, is a junior at Birch Wathen Lenox; Sebastian Oppenheim, the 16-year-old “player,” is a sophomore at the Ross School in East Hampton; Taylor DiGiovanni, 15, is a student at Stuyvesant; and Camille Hughes, 16, is a junior at the Nightingale-Bamford School. (Nightingale recently sent out a letter to parents and alumnae, clarifying that the school did not O.K. Ms. Hughes’ participation and advised against it.)

“Maybe the parents are thinking that this is a good opportunity,” Ms. Goldman said. “But … the focus should have been on college admission, not who’s hooking up with whom.”

Ms. Goldman then confessed that she’s writing her own (fictional) series about the world of private schools. Title: Admissions Impossible. She said MTV and the CW are both interested.

—Additional reporting by Caitlin Keating and Eliza Shapiro

ialeksander@observer.com