Watched my oldest brother challenge Dad one night.

Big bro was 18 and came home after curfew again. Dad was in his face

and bro threw a big haymaker, Dad ducked it

and came back with a nasty combo that sent brother straight to the ground.

He then stood over him and told him "it takes alot more than what you have"

Dad had some crazy strength that came natural to him, or so I thought.
I remember when he was 45 I asked him how he kept his arms in shape. He then did a handstand against the nearest wall (he weighed 230) and pumped out 50 vertical pushups. He said he did this every morning before he woke us up for school.
I decided I was never going to challenge the old man.