In the lobby of the library in my neighborhood, there is a square glass-topped display case with the intriguing sign “Things People Collect.” It draws me every time I’m there, to peek into the curious favorites of other people’s keepiness. I have dawdled over marbles in every color and pattern, vintage ceramic flower planters shaped like lambs and ponies, and a dizzying array of Pez dispensers.

I once installed my own collection there for a smug month; miniatures from dozens of places I have visited around the world, such as a pinkie sized Eiffel Tower and Plymouth Rock as a pebble. I like my miniatures because they are, of course, small, and they remind me warmly of places and things we did there. Noble purposes for a collection.

Why we keep what we keep is a mystery. I mean collecting, not its more insistent and unwelcome cousin, hoarding, which by now has its own entry in the DSM5, and differs in many respects, including that collecting is usually by choice, not compulsion. Not all collecting is by choice, of course. Once you admit to liking a particular category of things, mere affinity can swiftly be transformed into collecting by well-meaning friends who are relieved to have a ready gift idea. That is how my mother started her girlhood collection of kitschy salt and pepper sets, although she soon realized she liked the idea of them more than the reality. Reversing that perception took her years of disappointed birthdays.

Maybe we keep things that remind of us things we’ve done or places we’ve gone, like my miniatures collection. Sometimes we are drawn to things that complement our inner being.

My collecting coexists uneasily alongside a frequent exhibition of Spartanism, which does not yet have its own entry in the journals, but should, under Traits All Mothers of Small Children Should Have. With Spartanism, you determinedly eject things from your life, such as the day I emptied my house of all the unconnected-to-anything cords, wires, chargers to things that no longer charge and extra long cables to A.V. equipment that doesn’t A. or V. Although my friend Anne believes I really do still have every stitch of clothes I have bought since the early 80s, I go through phases in which nothing in my or anyone else’s closet in my house is safe. I plead guilty to having pitched the paper while my husband was still reading it, and once got rid of a box of slides from my grandparents’ attic dating from the 50s without even opening it.

I have also deliberately sabotaged my collections, in order to keep them from growing. My last kitchen redo included a non-magnetic stainless steel refrigerator; now I have nowhere to display my hundreds of magnets, so it is OK to stop bringing them home. Some simply die a natural death; with the demise of smoking in public watering holes, no one makes matches with clever bar logos anymore. Does that make my thousands of matchbooks more or less interesting?

I am at the point in my life when purging is more attractive than acquiring. Unfortunately, so is my mother, and frequently her outlet is me; many the mom night when she brings another load of “my things,” which I reluctantly take, knowing these items of questionable sentiment will soon hit the Goodwill pile. I look forward to the inevitable downsizing of the house, as my clearing out will then finally have purpose and justification.

Until then, I resolve that collecting will be as it should; narrow, focused, and only of those things meaningful and symbolic. However tempting it is to continue acquiring decorative plates for my kitchen, knowing that I now have enough is both liberating and satisfying. I will revel in the seashells I have without needing to pick up any more. I will collect experiences, and memories, and emotions; all things for which I have unlimited storage. Although I can never fit them in a display case, they will never be purged from my heart. Or have to be dusted.