Interesting Yet Perculiar Habit of Fathers

I noticed that fathers (at least in our parents' generation) seem to have this very interesting, yet perculiar habit of persisting in watching TV till they fall asleep in front of the TV. Up till now, I still don't understand why they would persist even when tired. Why not just go to sleep? Or do something else besides just watching TV? I find this such a generation gap coz nowadays we youngsters have more variety of things to do...