Sara Blakely's father apparently asked his children at the diner table how they failed that day.

Not a personal story, but one that I'll remember for my own kids when they grow up.

https://www.businessinsider.com/spanx-founder-sara-blakely-r...

Edit, some other knowledge I read: Richard Branson's father used to repeat: Isn't life wonderful. His mother would put him in front of a mirror and show how it reflects badly on him when he would badmouth other people. (I don't have the exact source on these two, some podcast I listened)