Curious, time-wasting question.
Just quickly, as this just occured to me:
Imagine that you are walking down the street, through a shopping centre (or mall, which is a stupid name, but that's for a whole other time...) or whatever. You see someone walking towards you. Just randomly, they burst out laughing.
Is this weird?
Cause I do it regularly. When I don't have conversation to occupy myself, I think about stuff. Today I was wandering around, when suddenly Bill Bailey's voice leapt into my head, saying, "...lunge wildly at the Pope!" And I just burst out laughing. I got a few stares, but it was kind of nice to have my own hidden joke.
I don't want to be carted off, is all.