A tale me Pops told me may illustrate the fact. Great Grandpa James lived on the same farm in west central Illinois his whole 92 years. Grandpa Joe was born there. Naturally enough, every summer Joe would load the family into some old wreck of a car and they would head out to see the extended family. The trip made further sense because Grandma Cosgriff, me grams, was from the same area too, so they could visit both sets of relatives.
One year when Pops was still in high school, him and a brood of his cousins were out in a large field shagging flies. Grandpa James, 85 at the time, noticed them, and went out in the field to watch. Eventually he asked if he might try hitting the baseball a bit. Now, he had a hernia at the time, and the grandkids knew it. But they also didn't know how they could tell their grandfather no, so they dutifully let him hit.
He was hitting well by Pops' account, just another guy tossing a ball in the air and thwacking it with a bat as it came down towards earth. Indeed all them grandsons were impressed by the old man. But Pops noticed Joe watching from a ways off, by the house he was born in, as if deciding something but not sure how to proceed. Joe Cosgriff being uncertain about anything was very unusual.
Grandpa Joe finally muscled up his courage and strode out into the field where his father had yet to relinquish the bat. He walked up to Grandpa James and said timidly (Joe Cosgriff speaking timidly?), "Dad, do you think you should be doing that, with your hernia and all?"
His father paused a moment to reply plainly, "Joe, I believe I'm about old enough to do as I please." He then proceeded to hit another 15 minutes. Joe put up no argument. He simply drew on a cigarette and walked back to the house.
It was surprising, yes. But as I said the other day Grandpa James had his way with folks, and as to Grandpa Joe, every man has his parameters.