Strolling with her partner on the Brooklyn waterfront, writer Deborah Copaken looks happy in love. But she admits to a few romantic regrets along the way.

"I can't imagine a single human being alive today, who has had at least one relationship, who doesn't regret something."

Now 57, Copaken says one of her big regrets goes back to when she was just 22. 

"Back in 1989, I was in Jamaica, and I met a young man," she recalls. "We'll just call him 'John Doe,' how about that? Just to protect his identity. And after a week together, I felt like I had fallen in love with him."

They briefly had to part ways — he, to London, to study theater, and she, to Afghanistan, to cover the war — but they soon reunited for `10 romantic days in England.

"I thought, 'This guy's it. I am in love. This is the relationship of my lifetime,'" says Copaken.

Alas, it was not to be.

"He said he was going to come visit me in Paris two weeks later," she remembers. "And I knew his flight, and I knew when he was supposed to have arrived. And I was in my apartment, waiting around, and he never showed up."

Back then, of course, there were no cellphones or internet.

"He had a very common name, like 'John Doe,'" says Copaken. "And it's not like you could find somebody back then with a common name, right? He's gone. He's gone."

Copaken says she felt sad, confused and heartbroken over John Doe, and asks, "I mean, how would you react?"

Author Daniel Pink believes that romantic regret can last a lifetime.

"We see people in their 80s, in their 90s, with these romantic regrets. It sticks with people,"
 he says.

Romantic regret — like all regret — is universal, according to Pink.

"Everybody has regrets," Pink explains. "I mean, we have evidence from neuroscience, from social psychology, from cognitive science, that the only people who truly don't have regrets are 5-year-olds. People with certain kinds of neurodegenerative diseases don't have regrets. And sociopaths don't have regrets. Everybody else has regrets." 

For his book on the subject, Pink collected more than 28,000 lovelorn regrets. The author reads several anecdotes from what he calls "the database of the regrets" — a vast inventory of unfulfilled love from 109 countries. 

"'Not asking out a high school friend on a date,'" Pink read from one submission. "He's 53. That's 35 years ago."

Pink says the most common regret is not taking action. He shows another submission written by a 49-year-old man in Rhode Island, who aid, "I dated a girl in college, but hadn't been experienced enough to know she was the one. I've never loved anyone as much as I loved her. I regret letting her go."

Another 54-year-old man from Wisconsin simply wrote, "Not telling her I Loved her!"

Jackson Arn, The New Yorker's art critic, thinks art is proof that romantic regret is universal.

"No matter what else the painting is about, no matter what else the work of art is about, you can almost hear it 'humming' underneath all the other melodies, so to speak," Arn says in an interview held at the Metropolitan Museum of Art in New York City. He adds that the wistful humming can be heard all over the museum.

"Rodin had a Ph.D. in regret as far as I am concerned," Arn says, and it's not just Rodin. Examples through the ages are in museums all over the world.

"It could be Edvard Much, falling in an out of love with an older married woman, and being so heartbroken that he turned the experience into a whole series of paintings called 'Love and Pain,'" he continued, also citing work by Edward Hopper and Kerry James Marshall, whose painting "Could This Be Love?" he hand-picked himself.

Arn sees a relationship between love, pain, regret and art. 

"Love has always been a great cause of pain," he says, "and art is sometimes the best therapy for it."

For Copaken, the best therapy is what she recommends in her book: learn from regret. That's what she did 21 years after her Paris heartbreak, when she finally tracked down the one that got away.

"I wrote an email, and I said, 'Hey are you the same John Doe that stood me up in Paris?'" Copaken said. "And he wrote ack pages and pages, saying, 'I did go to Paris. I arrived in Paris. I didn't have the piece of paper with your phone number on it, I ended up staying at the youth hostel and I never found you again."

Copaken and her old love reunited for lunch on a bench in Central Park. But, unlike the movies, they did not then ride off together into the sunset. Both were already married.

"It's not that I wanted to marry him. It's not that I wanted to blow up two families … that would have been terrible, right?" She says. "But it did make me understand what was lacking in my marriage. I realized at that moment that my marriage was faltering, and I needed to get out of it."

This is what brings us back to that Brooklyn waterfront. Now divorced, Copaken is in love today with someone new — and happier, she says, because of her past regrets.

"You can choose to decide in your life whether regret is just going to stick on you like a cold, wet blanket, or whether you can use that regret as fuel," she says. "If you use regret to make changes, positive changes in your life, then regret is the best fuel in the world."

Produced by Amiel Weisfogel. Edited by Steven Tyler.

In:
• Valentine's Day

Susan Spencer

Correspondent, "48 Hours"