It's the nature of all living things to extend their life as much as possible. It's in the nature of being human that we think what happens to most isn't going to happen to us - I am the outlier. I'm the one who's going to be vigorous and sharp as a tack until I'm 95. Thing is - <i>someone</i> will be, and it might be me! So we keep going. Going and spending a lot of our country's financial resources.