I love slapstick standup comedy (Robin Williams and Monty Python rule), but I never get the gist of any sort of a "practical" joke.
You know those jokes, where somebody pretends to be serious or mean or hurtful, and then you react badly to it, and then they laugh because you reacted badly to it, and then they try to releave you because "it was just a joke", but you don't get it because you're still trying to adapt to the comment they made, which was ment to be "the joke".
I also have a very bad problem with laughing at things in which most people think as foul, eg. swearing (from any person and in any possible context), and graphic violence (such as those bloody battles in Breaveheart and Saving Private Ryan). Despite being diciplined by both myself and my parents, this is still a very bad issue with me, and may possibly (I'm not certain about this) be due to AS. 