A friend of mine (30yo) has really old parents (like 80yo i guess) and it seems that her grandparents also were "old parents" because she recently dropped rather casually : 'Oh yeah, my grandfather fought in the boxer rebellion' and that just blew my mind.
If I do the math, yeah it tracks but still, it was her grandfather. For comparison, in my family the person alive during the boxer rebellion was my great grandfather and he was a child at that time, to have fought during that time it would've been my great great grandfather.