This is just my pet theory, but...What meaning might there be in reminiscing of the dead?is the moment when nobody is left to remember them.I think that the moment people truly die,That nobody can prove whether that person lived their life to the fullest,isn't that far too sad?...Professor, Rei cannot understand this "nostalgia" you speak of....Of course, biological death is when the heart, lungs, and brain cease to function....Well, here's the thing.