Experts weigh in on the psychology of romantic regret: "It sticks with people"

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.