Culpa

I called to make a reservation to go to SIGCOMM. The travel agent asked where I was flying to, and I said, "Pisa, Italy". I hear a lot of typing, perhaps a few "return"s, some "tab"s, several minutes pass and then she says, "That is pisa with a Z?". I say, "Uh, No. With an S." She says, "Oh, that explains it. I need to brush up on my I-talian". Type, type, type, ...

I saw the following claim: if x^3 +x is divisible by 4, then x is not odd. "Explanation" from a well known source. If x=1, that is true. Also for x=3, 5. So, true in general.

Reminds me of the book: Misteaks and How to find them before your teacher does, by Barry Cipra.