However, I have to confess that to whenever I hear that someone aged 90+ (80+, even) died, I don't really feel sad. Actually, I feel an urge to praise this person's achievements, as I'm aware we are all mortals, and death is unavoidable.
I prefer to rejoice in how much this person has witnessed throughout her life, how she had enough health to keep her wits until the end, how she could raise children, grandchildren, and even know her great-grandchildren.
What else can we humans aspire? Living forever is out of question. As soon as we are born, we are bound to die. So it's a pretty good life to be able to reach a good age, knowing that all our dear ones are set for life, raising families of their own, and living their lives the way that is best suited for them.
This is not just theory. I felt this when my grandfather died, aged 95, when my grandmother died aged 96, and when other people I knew died old enough for their deaths not really come as a surprise.