Before we get to the bad news, let’s agree that North Beach, the West Coast’s most-storied Little Italy and the richest vein of Beat Generation memories anywhere, can still deliver a moment.

As you line up for morning cappuccino among the young and old bohemians at Caffe Trieste, you spot a few who may have been present at its opening in 1956: one with bell-bottoms and a ukulele; one in a jacket that says “Rent Is Theft”; and one who is so focused on what she’s typing that she might bite through the pencil in her mouth.

As you shoulder through a crowd outside Golden Boy Pizza, you discover yet another line at the door of Sotto Mare, where the cioppino is king and the walls are crowded with big fish and old photos.

“This is the only real neighborhood that’s left in San Francisco,” Louis Samuels, a longtime resident, told me. “The tourists have been here forever, so they can’t (foul) it up.”

But from many angles, it looks like low tide in North Beach. Its retail vacancy rate ranks among the highest in the city. One city report calculated that 45 of 219 storefronts were empty at the end of 2018.

The empty spaces didn’t seem that numerous during the four days in early August I spent wandering the neighborhood. But people are talking and changes keep coming.

This might be a good moment to grab a mental snapshot of North Beach before the next wave of change, to grab a meal that involves tomato sauce, browse one of the nation’s most storied bookshops (City Lights) or lay your hands on fine ceramics from Perugia at Biordi.

Or just drink where Jack Kerouac drank (Vesuvio Cafe). But not as much, please.

While you’re at it, remember someone is always remembering how much better this neighborhood used to be.

The Ohlone were entitled to say it when Spanish colonizers grabbed their land in the 18th century, followed by gold seekers in the mid-19th, and Italian fishermen in the late 19th.

All the world said it in 1906, when the great quake and fire leveled much of the city. I’m betting somebody said it in the 1920s, when the San Francisco Art Institute moved in.

Allen Ginsberg, Lawrence Ferlinghetti and Kerouac arrived in the 1950s, leading the most notorious invasion of poets, painters, dreamers and loiterers the city has ever seen.

All these years later, the fascination continues even as details evolve.

“This is cyclical. I’ve seen this 15 times,” said Jimmie Schein, co-owner of Schein & Schein Antique Maps and Prints. “North Beach is simply suffering from what San Francisco is suffering from.”

The tech millionaires. The homeless. Within two minutes, Schein told me “I love it here” and “We are failing miserably as a city” — and clearly meant it both times.

“We’re always fighting in the neighborhood for something,” said Blandina Farley, who has been leading North Beach tours for nearly 20 years. A few minutes later, she pointed out a one-bedroom apartment. “About $4,100 a month,” she said.

Meanwhile, at Molinari Delicatessen, open since 1907, “It’s not the same, the way it used to be,” said Nicholas Mastrelli. “And that’s not necessarily a bad thing. ... I’m really excited.”

Mastrelli, 23, is the fourth generation of his family to stand behind Molinari’s counter. Now he’s adding gluten-free pasta to the inventory but still selling old-school sandwiches that bring crowds at lunchtime. Order the Molinari Special Italian Combo Sandwich.

Here, as tides of change roll in, are several lessons from North Beach now.

There is no beach. Once upon a time there was a beach. But in the late 19th century, as San Francisco’s leaders used landfill to create more real estate, Fisherman’s Wharf grew and North Beach found itself landlocked, with Chinatown to the south and Coit Tower rising from Telegraph Hill to the east.

Also, there are no cigars at Mario’s Bohemian Cigar Store Cafe, there are no live worms at Live Worms Gallery, and Original Joe’s isn’t in its original location and has never been owned by Joe.

There is no Italian restaurant shortage. Several have closed, dozens remain, and a few are new, such as Barbara Pinseria, specializing in rustic Roman-style pizza. Some have great food. Some have Italian owners who arrived in the ’80s or ’90s. Some have achieved maximum kitsch through liberal use of cherubs, murals, carvings, lights and bibs.

None is a major chain operation, because that’s illegal here. And none is perfect.

So you eat around.

Show up early to beat the line at Tony’s Pizza Napoletana; it promotes its prizewinning pizza Margheritas by making just 73 of these gooey yet crisp pies per day.

Get into a deep conversation with a meatball sandwich at Mario’s Bohemian Cigar Store Cafe. Linger over ravioli as Dean Martin sings “That’s Amore” above the old-school tumult of a Friday night at Sodini’s Green Valley Restaurant.

Nip into the calm, contemporary interior of Ideale, whose owner, Maurizio Bruschi, came from Rome in 1986.

Italians have seniority here, but they also have company. Step beneath the twin white spires of Saints Peter and Paul Church and admire the Italian marble and stained glass windows. Imagine Joe DiMaggio as a schoolboy running up and down the stairwells in the ’20s. Then check the schedule for Sunday morning Mass. At 7:30 and 8:45, it’s in English. At 10:15, Chinese. At 11:45, Italian.

Ferlinghetti may live forever. Even if he doesn’t, his City Lights Books might. Ferlinghetti, who co-founded the bookstore in 1953 and published Ginsberg’s “Howl,” celebrated his 100th birthday in March. He mostly stays in his nearby apartment while the three-level shop swarms with lovers of literature and liberal politics.

The Beats go on. Across the alley from City Lights, there’s Vesuvio Cafe, where Kerouac, Ginsberg, Neal Cassady and many others huddled and where precious little seems to have changed since its opening in 1948. For a perch with a view, head up the stairs. For a similarly timeworn, artsy setting with far fewer tourists, cross Columbus to Specs’ Twelve Adler Museum Cafe.

To learn a little more about the Beats, cross Columbus to the Beat Museum, which has vintage hipster photos and first editions, an old mimeograph machine, one of Cassady’s shirts and an electric organ attributed to Ginsberg.

Don’t forget the focaccia. There aren’t as many North Beach bakeries and pastry shops as there once were, but I like Stella Pastry and Cafe for coffee and a sweet, and Caffe Greco for a modest breakfast.

But for seniority and focus, nobody beats Liguria Bakery on Filbert. The people at Liguria do several varieties of focaccia to go and nothing else. Cash only. Get in and get out.

Beyond Columbus Avenue, rewards await. Columbus is the spine of the neighborhood but it’s also the beaten tourist path. Upper Grant Avenue has a more pedestrian feel that draws locals to galleries and boutiques, and antique maps and prints in the snug confines of Schein & Schein.

“First map of the city!” I heard Schein cry out one afternoon as a customer considered a reproduction from the 1850s. “You’ll notice that there’s no Columbus Avenue. They won’t put that in for years.”

And once they did, you can bet someone complained that the neighborhood would never be the same.