My mum has written the definitive post about my grandfather. I still can't really be upset that he's dead, because both he and I were aware of the impossibility of the concept. My grandfather was immortal.
He projected an air of immortality wherever he went - from his "I'm king of the world" pose in photographs, to his undisguised contempt for "old codgers", most of whom were a decade or so younger than him.
I remember thinking Hagrid ludicrously naive when he gently suggested that my grandfather might not, actually, live to be a hundred.
In conclusion, it's equally ludicrous now that everyone's saying he's "dead". I saw his body, of course, to check - but they'd shaved off his beard just before I last saw him alive, so it looked nothing like him (he hated his face without hair, I have no idea why he consented to the procedure).
Now I'm thinking about it, this might be considered the "denial" stage of grief. Er... NO IT ISN'T.