San Francisco is the most romantic city in America. This claim is written on cocktail napkins, delivered by the tourist board, supported by statistics. But consider San Francisco’s romantic oeuvre. There is Lawrence Ferlinghetti’s poem “In Golden Gate Park that day,” which equates marriage with coma. There is Dashiell Hammett’s morally opaque detective Sam Spade, who slept with his partner’s wife and turned another lover over to the cops. There are a dozen films about Alcatraz; there is Bullitt, with its romantic ennui between Steve McQueen and Jacqueline Bisset that was overshadowed by the famous car chase. There is Clint Eastwood’s Dirty Harry, Alfred Hitchcock’s Vertigo and the true story of the 19th-century British photographer Eadweard Muybridge, who settled in San Francisco and, at the age of 42, fell in love with a 21-year-old woman named Flora Shallcross Stone. In 1874, two years after they got married, she gave birth to a son that turned out to be the child of her lover, Harry Larkyns. At a party, Muybridge did away with Larkyns (but was later acquitted by a local jury). His marriage, understandably, suffered.

On the plus side, romance novelist Danielle Steel lives in San Francisco.

My wife, Grazyna, and I flew there for a romantic weekend. It was only the second time in nine years we had been away together without our two children. We walked along the Embarcadero, the lengthy promenade along the Bay shoreline, and stopped at a restaurant and ate oysters and drank a cold Sancerre and stared at Oakland across the bay, which, from a distance, looked lyrical. After oysters, we searched for chocolate, walking to the Ghirardelli chocolate factory past an army of street buskers, among them a man singing the Rolling Stones’ “Mother’s Little Helper,” accompanied by a banjo, and a little further along a drummer who set his drumsticks on fire and put them in his mouth.

“You know what would be a good act?” I asked my wife. “Two mimes doing the car chase from Bullitt.”

“Why,” my wife replied, “would anyone act out a car chase?”

“A seminal car chase. And one that resonates locally.”

“It’s a dumb idea.”

“It’s better than that trapped-in-the-box thing.”

“I don’t think mimes team up. They work alone.”

A man alone has no chance, Hemingway wrote. He is unfinished, lost. A woman, if the magazines are to be believed, has it even worse. On vacation, it is a habit of mine to imagine the lives of people I see. I looked at the couples, some of them unlikely seeming, others cozy and inevitable looking. What keeps them together? Whatever became of their first love and all those that came after? The romantic inventory contained in each of us slowly fades. “To view each loved one blotted from life’s page,” as Byron wrote. “And be alone on earth, as I am now.”

I ate a brick of dark chocolate while listening to a man sing “John Henry.” Three blocks from the chocolate factory was the San Francisco Art Institute, where a 1931 mural done by Diego Rivera covered the wall of a chapel. In the San Francisco Museum of Modern Art, Rivera’s painting The Flower Carrier hangs beside Frida Kahlo’s self-portrait. Rivera left his wife for Kahlo but then had several affairs. Kahlo had an affair with Leon Trotsky (and was later charged with his murder) but returned to Rivera. Their relationship was described as a union between an elephant and a dove. They divorced, but it lasted only a year, and they were together until Kahlo’s death in 1954, championing each other’s work, soulmates.

In the evening, we had dinner at the Grand Cafe, a beautiful room with massive Art Deco chandeliers giving a diffuse yellow light that fills the room with a seductive glow. We sat in a banquette and had a wonderful dinner and ate figs and cheese sorbet and had a glass of port and melted into the plush banquette in a state of romantic paralysis. After dinner, we walked down Geary Street to Union Square and sat on a bench and talked of romantic casualties. Will this friend marry? Will that couple collapse? Who, I asked rhetorically, are they kidding? I give them a year at best. In front of us was Macy’s seven-storey facade, its crisp, well-lit square windows resembling a giant vending machine: If you put $500 into a slot, a Donna Karan jacket would be pushed down to you.

Two women walked by, arm in arm. They were in their 80s, identical twins wearing fur coats and cowboy hats and white go-go boots and two kilos of bright makeup. Had they simply outlived their husbands? Perhaps no love was ever able to penetrate their secret twin world; they had been the loves of their lives.

We walked back to our hotel, past a Jimi Hendrix-tribute busker, past a man asking for change who complimented my wife for being younger than me, past a British performer doing Pink Floyd’s “Another Brick in the Wall” on a Hammond organ and a hundred couples pouring out of a theatre, leaning into one another with whispered intimacies. In the lavender hallway of the Clift hotel, under Philippe Starck’s remarkably restrained lighting, there was a short, muscular German man with a shaved head wearing bicycle shorts. He was standing with an Asian woman who was over six feet tall and dressed in black evening wear. They were holding up a video camera and looking at movies of themselves and laughing as lovers laugh.