I had a great-grandmother that kept very, very busy after retiring until dementia took over: The other great grandmother complained at 95+ that her knees wouldn't work well enough to keep busy. And this is how folks that feel fairly healthy tend to be, as long as they have enough money. Don't get me wrong: Pretty much everyone slows down when they age, and a lot of mundane tasks can easily get more difficult or take more time - but folks are still busy with a full life.

And then you start hitting a sliding scale, and poor health, poverty, lack of transportation and/or wheelchair access, and a slew of other things makes it really easy to wind up being the person that sits at home. The other unfortunate reality is that some of the folks are sitting because they are dying. I've not yet died, but I suspect it tires you.

I also don't think this is a trend that will stay: I'm 42, and I have a completely different relationship to television than my mother. Unlike her, I rarely sit down and simply watch a show - and I know lots of folks like this. Games and hobbies and communication with others and all this other stuff is going on. And assuming we can still use our fingers and wrists well enough, I think this will stay.