I've heard from doctors that the people most affraid of death are Catholic Nuns.

Whoops, that was off topic.

That would certainly be a reason JCL. You notice how so many rich and famous people are apt to try and hang in there as long as possible. The Queen Mother is a good example.

Not just that though. You can see from the replies that a lot of people are quite religious about this subject. Also, there are people who think they'll be overwhelmed with sorrow at their long life experience. I asked one of my students, who is a budhist, this question. She said it doesn't matter to her when she dies as she won't really be dead, but somewhere else.