Take death for example:
A great deal of our effort goes into avoiding it.
We make extraordinary efforts to delay it,
and often consider it's intrusion a tragic event.
Yet, we find it hard to live without it.
Death gives meaning to our lives.
It gives importance and value to time.
Time would become meaningless if there were too much of it.
If death were indefinitely put off, the human psyche would end up...
Well, like the end of a twilight zone episode.

Excerpt from-
The age of spiritual machines:
When computers excede human intelligence

By Ray Kurzweil