My granny (Mom's mom) is really a Super-Gran. Why do I say that? Cos even though she is already nearer to 90 years-old and her movements are noticeably slower, her brain is still as sharp as any well-polished knife! I realised this recently as I noticed that my usual banter with her as increasing becoming more funny. Her responses are really sharp and quick and her comebacks are really, really funny... something you'd normally not associated with someone of her age, and I am so proud of her. I really love her to bits.
Btw, Super-gran was this UK show that I used to watch as a kid. It was about a very old, bent-over lady who can become a super-powered grandma when some yound kid is in trouble. It was hilarious as she could perform feats that would shame even Superman! :) Moreover, she was also armed with a wicked sense of humour... just like my very own Super-gran!