Excited by low temperatures. Also by certain chemicals.

So I’m reading something today and learn that the same neurotransmitter (TRPM8) that is excited by low temperatures is also excited by certain chemicals, such as menthol. I always assumed that menthol’s coolness was on account of rapid evaporation, even though it’s just as cool in a closed area (say, in one’s closed fist) as it is on an open one.

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.