You know, thinking about it, I can’t figure how monthly calendars are even supposed to work. “I don’t know what day it is, so let me look at a grid of up to 31 days that it might conceivably be. Oh, that helps!” If we advanced this scheme about, say, long division we’d never buy it. “286 divided by 13? Oh, it’s something between 15 and 45 — of course! 22!”
And yet it does work, and I know it works because I’ll put up monthly calendars, sometimes, and not cross off dates as they’ve arrived and I can still work out what day it is from looking at all these options. That can’t happen, so I guess I have to conclude that I don’t exist, which could explain a lot of frustrating interactions I have with the Internet service provider.