A、Because they cannot stand the continual nagging of their children. B、Because they have to give in to their children’s demands.

M: You know, Chris, my grandpa told me this story once about his dad. It’s actually pretty sad.
W: What happened? Ryan.
M: Well, my grandpa said that his father never hung out with him or played ball or anything because he was really old. I guess my grandpa was born when his dad was like 50 or something.
W: Right, so he was too old to play basketball and stuff.
M: Yeah, and then when my grandpa was about 18 his dad died. The last thing his dad said to him was that he was sorry they could never play ball together.
W: Wow that’s really sad.
M: I know. So my grandpa decided he would never let that happen with his kids, and I think he probably told that same story to my dad so that he would remember too.
W: That’s cool. I think it’s so lame that my dad just doesn’t get it. He’s too busy thinking about work or whatever.
M: Yeah, maybe you should tell him the story.
W: That’s a good idea.
M: Dads can be really thick-headed sometimes but if you tell them enough they will finally understand that you mean it.