“Who is the truer owner? The more original owner? The one who goes back the furthest? Or the one who lives there now?” said Gretchen Rubin, author of several books, including “Outer Order, Inner Calm.” “What does it mean to own a house?”

Ms. Rubin is not above putting her mark on spaces that were once hers. After her grandmother died, Ms. Rubin, who was in her 30s at the time, took a knife and carved a nick into a built-in cabinet before her family sold the house where she had spent so much time. “I remember thinking I would really like to come back and see if this nick is still here,” she said.

We often want to check in on the places where we once lived. A third of American adults have visited their childhood homes in what Jerry M. Burger, the author of “Returning Home: Reconnecting with Our Childhoods,” describes as a “widespread phenomenon.” We may take these journeys because we want to remember our youth — and what better way to do it than by walking around a house that’s no longer yours?

For most of us, the experience is positive, so long as the house is still intact and bears some resemblance to what it looked like when we grew up there. Big changes made by other people after we’ve left usually make us unhappy. And if you show up to find the house has been demolished and replaced with something else, expect to feel devastated.

“There is this need to feel that your childhood still exists in your memory and it’s an important part of you,” said Dr. Burger, a professor emeritus of psychology at Santa Clara University.

But what happens when someone shows up at your house with fond memories of a time before you lived there? You may enjoy hearing stories about your home before it was yours, or you may find the experience unsettling, like someone is trying to lay claim to a place that is rightfully yours.

In 2017, Pippa Biddle was unnerved when she learned that her new boyfriend, Benjamin Davidson, and his family had, by sheer coincidence, once lived in the house across the street from the house where she grew up in Katonah, N.Y., and where her parents still live. It was unsettling because it made clear that her house had a history she was not privy to.