I first came face to face with the cold facts of mortality when my mother died two years ago, I had had bereavements before but at one step removed.
It caused a massive shift in my psyche and I don't think I have dealt with it properly, its not the thought of no afterlife that affected me so strongly, that sounds like a good thing to me.
I don't really know why it affected me so strongly, perhaps I should stop ignoring what happened and examine it properly.