If you are not already familiar with it, here is the unexpected hanging paradox for your erudition and evelasting frustration.

I prefer the version of the paradox where a teacher says that a quiz will be given some day in the next week, but the teacher does not say what day it will be. What I liike about this is that it can be given a practical twist. If the students know the day of the quiz then they can cram for it the night before. I have never seen this version of the paradox expressed in that way. I think that talking in terms of something that can have consequences gets rid of a lot of nonsense like talking about the meaning of the word surprise

I have been trying to think of an even better story with a practical advantage of having knowledge of the event. I have not come up with anything that I like. Can you think of something?