He was 99 and had the best healthcare the world can offer - why is everyone so stunned and shocked that he died?...
I don't think that it is so much that people are shocked that at 99 he, or any other celebrity, died
per se.I think it more that the news of it starts one thinking [something] along the lines of: Wow... 99! That's a long time. I remember when I first heard of him/her and I was (some age). And now I'm (this old). Time flies.
And then---if you are of a certain age, or older, you start thinking about yourself getting older, and (even if you are in relatively good health) your own inevitable death.
And believe me, you don't have to be really old for those thoughts to start occurring every time you hear of someone dying, whether you know them personally or only know of him/her via the media.
It's one of those existential moments that we all have whenever we experience a very human event.