When a review of my novel, Well-Heeled, took special note of the protagonist’s estranged husband, Larry the Loser, my real husband was not amused.

“Larry the Loser is me,” he lamented.

“What are you talking about?” I said to him. “Larry the Loser is a character in my book. He doesn’t exist.”

“How come his name begins with an L, just like mine?”

I argued that I had first named the protagonist’s husband Harold. I was looking for an ordinary American name that many Jewish men had. I changed the name to Larry when I realized I had already assigned Harold to another character.

“Larry the Loser watches WWII movies on TV, just like me,” he said sadly. “That proves it.”

“It proves nothing,” I protested. “Half the men in the country watch WWII movies. That’s why they are always on TV.”

“He likes vintage watches, just like me.”

“So do thousands of other men. Look at all the stores that sell them.”

Hawthorne once had to plead that he was not writing fiction but “the truth of the human heart” in order to satisfy his critics, while in order to satisfy mine, I have to claim that I’m not telling the truth about anything.

The real truth, however, is that all fiction is grounded in some truth, somewhere. Even in the most far-fetched, loopy sci-fi novels, the characters think, feel, and act like us—or else some cockeyed version of us—and somewhere there is an intersection with “the truth of the human heart,” where real details keep the story from flying off into space.

Since writing teachers always say “ write what you know.” I started my creative process with a neighborhood—the Upper West Side of New York—where I have lived most of my adult life. I created a protagonist who also lived there.

My protagonist and I, however, very quickly diverged, after I posed a series of “what if” questions to myself: What if the protagonist left her husband instead of staying with him? What if she had no children instead of two? What if she were the owner of a discount shoe store instead of an editor at a publishing company?

Once these became the protagonist’s circumstances, she set out on a road that would lead her further and further from me. She would have to be braver, bolder, poorer, and more impulsive than me. She would interact with illegal immigrants, confidence men, cross-dressers, gamblers, gangsters, and local “entrepreneurs” with questionable business practices, the kind of people I have only passed on the street. Instead of children, she would have a ditzy sister to take care of. She would thrive on danger, run toward risky situations and become attracted to a cop.

The more I wrote, the more not-me the protagonist became.

All that said, since we both live in the same neighborhood, are close in age, and both Jewish, it is inevitable that we would share certain attitudes and traits—liberal politics, an interest in books, a love of argument. My protagonist and I sometimes jog in Central Park; we both enjoy an occasional vodka when things go wrong. These details help make my protagonist feel real—but they do not make her real. And they certainly do not make her me.

Part of the fun in writing fiction is scrambling up real details with invented ones, concocting an imaginary character out of bits and pieces of real ones like pasting the wild red hair of my neighbor Louise, a kindergarten teacher, on the head of Natasha, a runner for the Russian mafia, transferring the political principles of my dentist, Morris Shapiro, onto the back of Jose, a Puerto Rican newspaper delivery boy, and tacking a few marital infidelities, leaked by my Aunt Sadie after too much wine, onto Larry the Loser.

Since my real husband is the only husband I have ever had, it was inevitable that some aspects of his personality would seep into my novel, but only after being put through the blender of my imagination.

In vain, however, I invoke “poetic license”; assert that particular details illuminate universal truths; repeat Arthur Miller’s words that after every performance of A View from the Bridge, someone claims, “You have told my story.”

For my part, I don’t think my husband has anything to complain about. Now, Erica Jong’s ex-husband, whose “ hairless balls” were described in Fear of Flying? He had a reason to complain—although if he did, I imagine her defense would have been similar to my own.

Roz Siegel, an editor and writer for more than 25 years, is the author of the mysteries Goodie One Shoes and Well-Heeled.