In fact, I “knew” that menthol’s coolness was caused by evaporation, even though this doesn’t stand even the slightest bit of active thought. It’s a trivial enough fact that I didn’t bother to expend any bandwidth on it at all, even as it was filed under “things I know.”

The point being that there are likely innumerable other “facts” sitting around in my brain. Hopefully the worst these will do is cause embarrassment as I wax knowledgeable at some dinner party, but I’m reminded how important it is to stay conscious of — respect, even — the breadth and depth of my ignorance.