[jmharvey]

Earlier today I mentioned to my first grader that when I was a kid we didn't have an ice maker in our freezer, and we just used ice cube trays, instead. He sat there for a minute, stumped, and finally asked, "so what made the freezer cold?"

It took me a minute to figure out what he meant, but finally I realized that he thought the way our freezer worked was that we had a machine that made ice, and the freezer was cold because it was full of ice. It's really easy to reverse cause and effect when you can't see what's happening.