I find the short version of that type of joke (something completely expected happens, in defiance of normal joke conventions) to be much funnier than the long version, for some reason. I also seem to remember there's a name for the class of jokes like that, which my friends and I spent a good twenty minutes amusing ourselves with at the time. Anyone remember what they're called? For some reason I want to call them Soviet or Russian, but I have no idea whether that's the correct label.

EDIT: Ah, my flatmate came to my rescue. Apparently they're called German jokes, after the German stereotype of humourless efficiency.