I think about that too sometimes coz I won't have children to rely on to visit, do stuff, when I'm old and going senile or worse. It's wise to look around at the really old people you see in life and who has company and who doesn't... there's a lot to learn from that.
I myself won't be rich enough to live it easy, so I just want to make damn sure that I'm still cheeky enough to get away with stuff, gracious enough to people who help me, and mad enough to be entertaining to ensure visitors. oh... and as long as I have the internet!!