I don't have much else to say, but I need to re-watch that episode now!
"Everybody thinks death is such a bad thing" primarily because we're 'built' to instinctively feel that way as much as any living organism is. Sorry if that's too crude an answer, but I think it's the most logical one.
It's a curiously self-defeating aspect of the human species that its greatest evolutionary advantage could also be its undoing.
As for dreams, I'm not sure what their function or purpose is. I haven't had many in a while, but aside from the rare blissful one they really are painful reminders.
"I'm a pessimist because of intelligence, but an optimist because of will." - Antonio Gramsci
"If he did advocate revolutionary change, such advocacy could not, of course, receive constitutional protection, since it would be by definition anti-constitutional."
- J.A. MacGuigan in Roach v. Canada, 1994