Despite our preparation, indeed, despite our age, [the death of a parent] dislodges things deep in us, sets off reactions that surprise us and may cut free memories and feelings that we thought had gone to ground long ago. We might, in that indeterminate period they call mourning, be in a submarine, silent on the ocean's bed, aware of the depth charges, now near and now far, buffeting us with recollections.
I had one relative who passed away but fortunately none others. So my sort of experience of it is quite limited, thankfully.