You've got a detailed post here. We learn everyday despite our age, but there's one thing i notice about elderly people. They find it dificult sometimes to ask us for help, even when you see that they need that help and you approach to help, they'll be as if you're mocking them or a kind of insult.

Your father is matured because he possesses that humility in him and open to learning. I also helped an elderly man in my congregation to set up his jw account, so truly elderly people can learn from the youth.