How about this?
There are lots of living great-grandparents these days, what with people living somewhat longer.
I'm 66; my maternal grandfather was born in 1888. So far, not so impressive.
But HIS father was 71 when he was born. I guess it was common back in the "old country" for a widower to marry a much younger woman if he was a man of means. Which in this case probably meant he owned more than two goats.
Do the math. My great-grandfather (about whom I know nothing whatsoever) was born in 1817. DURING THE NAPOLEANIC WARS!!! The President of the United States was James MADISON, one of the Founding Fathers (not that my great-grandfather ever heard of the United States!).
Yikes!
Alan