“I think a lot of the people that are moving into the city don’t have a full understanding of what is being paved over or forgotten about,” Mr. Casseus said. “It’s a hard thing to swallow sometimes.”

A lot has changed from a quarter-century ago or so, when our fair city was best known for graffiti-decorated subways, blasting boom boxes and the faint smell of urine rising from the summer pavement. There were no Tinsley Mortimers, no hedge-fund gods. No $1,000 pizzas or latte factories, no $50 million mansions or elliptical trainers at Equinox. Indeed, in 1975, the city’s government declared bankruptcy. “Ford to City: Drop Dead” blasted the Daily News, after the President refused to bail us out, and, two years later, it seemed like a serial murderer named Son of Sam was determined to deliver the sentence.

The rest of the country thought we were goners, collapsed in a sputter of crime, crack and fiscal disaster. There were landlords burning down their buildings—you couldn’t give ‘em away! Hookers hanging out on 83rd and Broadway—right near Zabar’s!

But you know what? We liked it.

The dog shit was piled so high in the streets you needed a mountain ax just to traverse the sidewalk—but we liked it. The buildings were so blackened by grime you could barely see them in the dark—but we liked it. The subways were so dangerous you felt you were descending into Hell—and we liked it, we loved it, hallelujah!

For a certain generation of New Yorker—a generation that came of age at the city’s economic nadir, but also in the glory days of Bella Abzug, checker cabs and CBGB—this city of yore seems as perversely lovable as some long-lost episode of The Magic Garden.

“It seems kind of weird to say that one would be nostalgic for times when you were scared to get mugged going out at night and riding the subways was taking your life on your hands,” said Dalton Conley, 37, an Alphabet City kid turned New York University sociology professor, who memorialized his childhood in the book Honky. “Yet I think there is something that’s lost.

“The old New York is kind of like an old spouse that you just complained about the whole time,” he said, “but then, when it’s gone, you realize you loved him or her.”

‘I WAS FLASHED ALL THE TIME’

New York has always been a breeding ground for nostalgia; constant change will do that to a place. But sometime in the last few years, between the outlawing of the squeegee men, the terrorist attacks of Sept. 11, 2001, and the coronation of Michael Bloomberg, this sentiment has been particularly overwhelming to those natives who took their first bite of chocolate at Barton’s Candy on West 86th Street in 1974 (now a Gap), bought their first Duran Duran album at West Side Records on Broadway, or perhaps got their first human biology lesson from some random guy in a trench coat.

“I was flashed all the time—that’s how a true private all-girl kid learned about the male anatomy,” wrote Liz Alderman, 32, a television producer and former Brearley lass, in an e-mail.

This is not mere Wonder Years, sepia-smudged longing for one’s childhood. It’s nostalgia for cheap rents. And wild, bizarro characters (New York was full of them once). And an era when investment analysts didn’t bribe people to get their kids into nursery school.

“I kind of feel like a foreigner in my hometown,” said John Sanful, a 38-year-old New Nostalgic from Harlem who runs an organization called Career Gear and gets misty about the Felt Forum, the old East Village and Apex Tech commercials. “You know, New York was always a place where there was an edge, and you could kind of drink in some of the curiosities it had to offer. But I just don’t feel that way anymore.

Now, he said, “it’s a sort of playpen for folks from out of town.”

Not everyone is sympathetic to this point of view. To some, any kind of wistfulness for the era when New York was teetering on the edge of total blight is plain old crazy talk—or at least self-indulgence.

“Get over it!” barked former Mayor Ed (“How’m I doing?”) Koch, who said that he has no nostalgia for the days when he got goose bumps just walking down the street at night. “Don’t live in the past!”

But for many who came of age in the bad old days, the past is precisely where they want to be—minus, perhaps, some of the dicier details. With voices husky and excited, they’ll regale you with anecdotes of their glorious urban educations courtesy of Fiorucci, Save the Robots and the porno stylings of Channel J (hello, Robin Byrd!). They’ll recite tales of 75-cent subways and $300 rents—on West End Avenue, no less. And they’ll tell you that the city of today—the city of Soho House, shiny condos and stupid socialites—is not New York.

“Just because you have a Time Out subscription does not mean you’re a New Yorker,” said a 33-year-old named Alison who grew up on the West Side and works in advertising.

“New York kind of sucks right now,” added Zoe Schneider, a 35-year-old graduate of LaGuardia High School whose nostalgia runs so deep she took time out from her labor pains—yes, she was about to give birth to her first child—to reminisce with The Observer.

In the (alternate) universe of Old New York nostalgics, Ms. Schneider is one of the reigning wistful spirits, a perennial pining soul who has turned her longing into full-fledged obsession, or at least a hobby. Each month, she throws a party called Magic Garden for born-and-raised New Yorkers—and only born-and-raised New Yorkers (an e-mail containing the name of the hospital in which the would-be reveler was born is one of the criteria for admission). Modeled on the old Monday-night Soul Kitchen, the party offers cheap beer à la the city’s less extravagant days, dancing and memory-swapping, and can only be accessed by those who have been given the historically apposite password—like, say, Unique Boutique, Alexander’s, the Decepticons, Lamston’s or the Astor Place hair-cutter. (Ah, the Astor Place hair-cutter, home of the mohawk and asymmetrical bob—now downsized by a Cold Stone Creamery). It has an invitation list of 2,000.

“It’s the one night where we kind of rule,” said Ms. Schneider of the parties where teachers, artists and writers replace the usual clubgoing crowd of bankers and Lohan-alikes. “I feel like it’s my city again.”

‘MUGGING MONEY’ MEMORIES

For today’s nouveau New Yorker—the kind who has just moved to Manhattan with dreams of dinner at Per Se and dancing at Bungalow 8—it’s almost impossible to understand the difference between the city as it is now and how it was 30 years ago: the summer of Sam, Annie Hall, disco and the July 13th blackout. The dirt has been Dustbusted from the sidewalks, the oddballs sand-blasted from the streets, the sky filled with deluxe penthouses. A million more people have joined the metropolis, but New York County now has the widest income gap in the country. Mazel tov, Manhattan!

New York, of course, wasn’t exactly the Paris Commune back then, either. Nonetheless, certain facts held true. In the Wast Village, an unemployed musician could get a gig playing cello in McDonald’s—and McDonald’s was still so rare that it seemed “exotic,” Mr. Conley recalled. Straight couples swung at Plato’s Retreat, in the basement of the Ansonia Hotel, while gay men got frisky at the New St. Marks baths. And, on the Lower East Side, a couple named Adam and Eve Purple roamed the streets in purple clothes on purple bicycles.

“The people who used to come to New York were freaks of nature,” said Ruby Lawrence, 34, a bar owner who was born on Manhattan’s West Side and lives in Brooklyn. “Before, looking different was the fun part of living here, whereas now it’s about looking the same.”

Ms. Lawrence has a long list of things gone and missed from her days growing up in Manhattan’s West 70’s. Back then, the Upper West Side was a shabby, motley place, where interracial couples went to live in peace, intellectuals and S.R.O. dwellers shared the same blocks, and jazz great Miles Davis could live without feeling, as he doubtless would now, like he stumbled into Romper Room. Then, as now, parts of the area were ritzy, but other parts were downright scary, like Columbus Avenue, where the junkies hung out, or the 72nd Street traffic island known as “needle park.” Among the local highlights were John Lennon sightings, McGovern’s bar (they’d serve anyone a drink), Lichtman’s bakery (for the bubbe in all of us), the Loews 83rd Street theater (where half the Upper West Side learned to smoke), and a certain folksy neighborhood feeling.

“It certainly wasn’t as clean, but there was a big sense of community,” said Ms. Lawrence, echoing a theme heard throughout the nostalgics’ chorus. “The first time I crossed Broadway myself, I had the guys from the garage watching out for me …. My parents would send me to the store and I could get stuff on credit. But now that’s totally gone. Now there’s a Barneys on my corner.”

There was, of course, a flip side to all this fuzziness, a grim part that explains why every Mike and Carol Brady didn’t just hightail it from the ’burbs to join this new utopia. There was crime and racial tension and drugs and, eventually, AIDS. It was bleak. And everyone had their story.

In the realm of bad New York happenings, the events of this era ran the gamut from disturbing but relatively harmless to scarring but not life-threatening to outright crushing (in a directly personal or, at least, psychic way). In the first category fell phenomena like, say, the guy who lit his pubic hair on fire on the subway. In the second, things like the 86th Street gang, which beat up a classmate on his way to a Bar Mitzvah reception, or the boys who got mugged time and time again (girls had it easier in that respect). And in the third? All the names that any 70’s or 80’s kid can recite like the catechism: kidnapping victim Etan Patz, the Central Park jogger, the Diana Ross concert riot, preppie murderer Robert Chambers, slashed model Marla Hanson, subway shooter Bernard Goetz, and the boy who was eaten by polar bears at the Prospect Park Zoo.

There were also, always, a few personal stories that lodged in one’s mind, stuck there for years—like the kid who got killed by a blow from a baseball bat at the local video parlor (on East 78th Street), or the bullet that came through one of your apartment windows.

And these were just the stories of the privileged types.

“I remember, there was just this fear,” Alison said. “I remember having to carry mugging money—$5. I remember having to know where all the Safe Haven stuff was. I remember all the bus ads with Etan Patz. There was just this fear, this fear of home, and I remember being really scared of the city.”

And yet, for many New Nostalgics, the memory of all this old fear is also a kind of badge of survivorship, a sign that you have earned your New Yorker’s stripes. Sure, you may have quaked and hated it way back when, but at the safe distance of 20 years, it just makes you tough, particularly compared to the neophyte New Yorker.

“I feel like I not only have a thicker skin, but a better appreciation for the city. I can handle a lot more,” said Ms. Lawrence, who had less kind words for the arrivistes.

Still, much as an old-timer might denounce the newbies who flash their Rolexes on the subway or prance through Central Park at night—what are they, crazy?—bravado, like nostalgia, is ultimately an unscathed person’s game.

Way back in high school, a 35-year-old St. Ann’s graduate named Greg Clayman knew a girl who was pushed in front of a subway. She was rescued right before the train came, and lived to make it onto the evening news. Years later, Mr. Clayman and his friends still marvel at the incident, still gape and gawk over it from time to time. But he doubts that she is about to whip the story out over borscht at Veselka.

“She is not about to romanticize the experience of being on the track while the train is coming barreling towards you,” he said. “She lives in Vermont, I think.”