A friend of mine and I were on a flight two weeks after september 11. We were talking about how aircraft navigate runways/taxiways/tarmacs/etc. One of his final responses to what I said was, "yeah, but without it, the plane might crash into a building."
(It made sense in context, but I can't imagine what it was like to overhear part of what he said.)
This is the same guy that shouted "watch out for anthrax!" at me when I walked to check my mailbox last week. He didn't see the USPS truck and mail worker that was standing nearby. I explained to the USPS employee (who recognized me) that it was only a joke and that he didn't know what he was talking about. Fun stuff.
*sigh*