Why is it that whenever someone jokingly anticipates something horrible happening to them thus resulting in the loss of the knowledge they carry in their head they say, “In case I get hit by a bus.”

Yes, buses do hit and kill people, but I think cars do much more often. I am nearly hit by a car two or three times every week — usually when someone is making a right turn on a red light and not paying attention to people walking.

I’m just wondering aloud, but is this part of some conspiracy against public transportation?