I don't see the point in gnu's story above of the woman's being 80. Why that? What had her age to do with the punchline? I must admit that I have a sort of Aristotelian attitude to jokes, that everything should be relevant to the narrative if they are to be fully effective. I know that over-analysis can be fatal to any joke thread; but I still don't see what her age had to do with it.

~M~