If everybody knows that death is inevitable, why do we find it so difficult to accept it when it occurs?

Don't get me wrong, it must be a shock and all when one minute they're here and the next they're not but once that shock has been processed, it intrigues me that people can no longer look at the world in the same way. It just shows how people's perspective on the world is constructed by those who surround them and not themselves and I don't know about you but that makes me kinda sad.