I often dream the answer to something I'm trying to figure out. Like night before last when I saw how I can make a fully dimensional "Nemo" cake for my 2 yr old niece's birthday in a few days. I also dream about things going on in the lives of others, & they later tell me that it happened. I often dream about stuff before it happens. Don't know why.   My Grandad was like that, too.
But jokes? I don't think I have ever dreamed of jokes, exept for the occasional nightmare about my ex.