Selfish?

When someone dies, do people mourn because they truly feel a loss, or because
they're afraid that the death was in part their fault and don't want it to stay on their
conscience?

I stumbled across this last night as part of a young girl's confession, and it has a sort of truth. What not everyone realizes is that nearly every emotion we feel is out of selfishness; this is why they are our emotions and not anyone else's. While we can act out of selflessness, we're not going to feel good about it.
True, there are those who take a sick pleasure in death. There are those who feel accomplished when avenging someone through death, or those who thrive off of reporting others’ deaths. However, the chief concern with a death that is not our own is the grief that settles in afterward.
In fact, in the case of death, mourning is only and always selfish. If you're sad that a person's gone, it is because you are missing them; not because you're sad that they no longer can enjoy life.
Not to say that this is a bad thing. If the point of life in the physical world was to be entirely selfless, then those you were sacrificing your own happiness for would be acting selfishly to accept your selfless offer.
A common misconception is that people are selfless when it comes to love; they say, “If they’re happy, I’m happy.” The second half of this statement is most important, however. “I’m happy.” In the end, you feel joy from your significant other’s happiness.
The word “selfish” has gained such a negative connotation. At most times, true, it does not denote something positive, but it’s the word that most describes human behavior—we’re all selfish. We all want what makes us happy, because being happy is the epitome of our existence.
While we shouldn't be piggishly selfish, we're put on this earth to serve God and be happy. So it's okay to mourn the loss of a loved one; it's okay to take that day for yourself. Although I definitely can’t say I know the meaning of life, I can say that life is enjoyed when happy; and the reason why we’re happy is because, ultimately, we’re selfish.