This morning I’ll be in the Berwyn neighborhood of College Park, Maryland—five minutes from my old apartment, now closer to an hour away—for my old parish’s annual rummage sale. Every year except one I’ve gone, since 2015. It’s fun, I always find something good, and I like seeing what’s going on in my old stomping grounds.

The older, densely populated suburbs in Prince George’s County have always been great for garage sales, thrift stores, and rummage sales. My guess is that it’s as simple as lots of people living there for a long time and accumulating a lot of stuff, including a lot of stuff that’s now worth money or isn’t made anymore.

When I’ve been to used-stuff sales of various sorts in newer areas, I can notice the difference. More of the stuff is new. And that means more of it is junky or uninteresting, or retailed for so little that there’s no real secondhand market for it. I don’t know how many ceramic trinkets I’ve seen at a garage sale, with the Home Goods label still affixed to the bottom...