To care about possessions can seem like a moral failing, like if these people were enlightened enough to know what truly matters, they’d be sending in empty photo frames. The holiday season especially can make people ornery about “stuff” and the companies that encourage us to buy it. But loving objects doesn’t necessarily make someone greedy or materialistic.

There are two kinds of materialism, according to Dr. Mihaly Csikszentmihalyi, a distinguished professor of psychology at Claremont Graduate University. Terminal materialism is the kind typically derided as shallow and empty—wanting things for their own sake, or to impress others. What inspires someone to save something from a burning house is more likely instrumental materialism, when “the object is simply a bridge to another person or to another feeling,” Csikszentmihalyi says.

While things are, on the one hand, just things, they are also repositories for the meaning people project on them. Religious objects are obvious examples of things that transcend their thing-ness: A cross is just two pieces of wood but for what it represents to Christians; a menorah is just a candelabra, except that it’s not. Similarly do people build meaning around their possessions—a gift from someone’s mother might represent her love; souvenirs could be reminders of places close to heart but far from hand.

“Things embody goals, make skills manifest, and shape the identities of their users,” write Csikszentmihalyi and Eugene Rochberg-Halton in their 1981 book The Meaning of Things. “Man is not only homo sapiens … he is also homo faber, the maker and user of objects, his self to a large extent a reflection of things with which he interacts.”

There is, of course, a continuum of how attached people are to their things; on one side the ascetics, on the other, the hoarders, most of us somewhere in the middle. Children often get attached to blankets or favorite toys—about 60 percent of kids in the U.S., by one estimate. For those kids, a teddy bear is not just a stitched mass of cloth and cotton, but something that signals safety, and maybe reminds them of the parents who gave it to them.

“As we age, the immediate need for those objects often declines, but that doesn’t mean that the attachment to them declines as well,” says Dr. Kiara Timpano, an assistant professor of psychology at the University of Miami. When a kid grows up, he might not need his teddy bear to calm him during a thunderstorm, but that doesn’t mean it’s not still important to him. It may be important because of the history and memories it represents, and because it’s been in his life for so long that it serves as an extension of himself.

In a 1987 literature review, Dr. Russell Belk examines this idea of the “extended self” at length, concluding: “It seems an inescapable fact of modern life that we learn, define, and remind ourselves of who we are by our possessions.” The loss of possessions, ones deeply associated with the self, can cause real grief, Belk finds. If your house was burning, and you had no time to save your favorite things, you might feel like you’d lost part of yourself.