There is a myth that autistic people don't understand jokes or sarcasm when I think that we do, but to different extents.
Personally I struggle most with sarcasm, especially when it's written, like on twitter for example.
I get most jokes, it doesn't mean I think it's funny though.
I really don't enjoy comedy, the only type I don't mind is the ones that laugh at things that happen in real life.
I can't stand sitcoms, I've never laughed at one once. I "get" the joke but it's just not funny.