Once, when returning to the US, I was asked why I was wearing a coat. Because it's December and I just flew in from Frankfurt, you dunderhead...

Weirder were the two times an agent suggested that with my background I should join an intelligence agency. I was working on dual CS and international relations degrees at the time, which I did not mention to the agent. I should really file a FOIA request on myself to find out what was in my file that prompted those questions.