I've been thinking about this recently, and it's the sole reason why I can't focus on an essay right now.
1: Why does death make people sad?
I've come to the conclusion that we are sad when someone dies because he/she was significant to us in some way. Family, friends, etc. However, if we mourn people's deaths because they were important to us, it is because we will never enjoy their company again, not because they died. If someone went to live in isolation for the rest of their life, they would be "dead to us". We would never enjoy their company again. If, when someone died, we could continue to communicate with them, death wouldn't be anything worth mourning.
2: With that point made, why is it such a big deal when someone who we didn't know dies? (hear me out here, I may sound extremely insensitive).
Take, for the best current example, the Haitian disaster. Yes, it is terrible that those people died, since life is the only thing we have; it is everything we have. Yet people can become very defensive when I tell them that while the death of those people is bad, I do not feel any emotion for the deceased. Once someone is dead, they are dead, and that's the end of it. If, according to my first point, we only feel sad about someone's death because they were important to us, why would we feel sad/concerned about the death of someone who was not important to us?
My second point wasn't really a point, but an open question that I would appreciate feedback on.
My only answer to #2 is that we are raised like that. When 9-11 happened, I was in 3rd grade. Were that to happen now, I wouldn't be sad/upset/concerned for the deaths of those people, but I would feel sad/upset/concerned because it was a strike to my country (which has meaning to me). However, when it happened, I cried and was sad because that's how everyone else was. It was proper etiquette, if you will. So what I believe is that we are raised to be sensitive towards human life, which isn't necessarily a bad thing, but it does us no good, either.
Feedback?
(tl;dr - forget you)