My dad sounds pretty much like yours, Schmange, but he's only 52 or something. Plus, his mom just died of Alzheimers, so you know it's only gonna get worse. And seeing as it's hereditary and all, I'll probably get it too. C'est la vie.

As for the joking around, I can say literally anything I want to my parents and they'll clue in that it's a joke. In fact, I attribute much of my sense of humour to my dad, and the fact that he insisted I watch shows like the Simpsons from birth, when many parents would have considered it too adult-themed or whatever for a child.