Why do deaths destroy us??

I watch a lot of 20/20, Dateline,  etc so I see a lot of people dealing with death. It is so traumatic! I've been through it, too, and it is always crushing. Lately watching Dateline I started wondering why?? Death has been certain since life began. It supposedly one of the two certainties of life ie "death and taxes". So why does it shock and devastate us? It also seems like man has come up with many ideas of Afterlife to make death easier to deal with throughout history and many find comfort there but it is still a huge tragedy for everyone.  Why in the thousands of years man has been here have we not come to peace with death? I have no clue and I don't deal with it any better than anyone else. The death of my Obi was the last one that crushed me. 

And now I look at facing my own death a lot and my biggest fear is how it might effect people who care about me. How do i make it easier for Jami, Jeanette and Jenise?? Can I?Even those who are fortunate enough to have strong faith in the Afterlife still grieve deeply. I am one of those. I just can't believe that death is the End. The other day Kira said she believes death is just final and that she is happy to believe that and everyone listening was shocked including me. It's good that she is fine with that but odd compared with how mankind has always needed the Afterlife belief. 

But my point is what I first said here.  Why haven't we come to terms with death?? Even with Kira's belief, or lack of belief? she will still grieve the loss of those close to her. I can't fix this any more than anyone else can but it's just been the thing that makes me go Hmmm lately.