being sensible, or something

I thought about how my knees and right foot have been feeling in the last few days, and just called the hairdresser to let them know I won't be keeping my appointment tomorrow morning.

On this short notice, there's a 100% cancellation fee, but going to get my hair cut tomorrow would definitely be sunk cost fallacy. The reason to call now was mostly so the stylist knows she has that half hour free, and also so I don't, tomorrow morning, foolishly change my mind. (It's late enough that I got their answering machine, which is fine, I don't need to talk to them about anything.)