I’m taking the kids to Atlanta tomorrow for a family reunion, and to visit cousins on my side of the family they’ve never met. This morning, my son woke up early, and came into my room. “Daddy, do we have to pack now?” he asked.

“No,” I said, “we’ll do that tonight. You know, I have that big suitcase that you helped me buy, and it has space for your stuff, if you want.”

“No,” he said, “I want to use my own suitcase.”

“Well, that suitcase”– which is unreinforced plastic– “has been on a lot of trips, so we should see what kind of shape it’s in.”

“Oh, it’s a rectangle.”