They nostalgically long for the security, imagined or real, of bygone days. Every age has had its challenges and uncertainties, but the imagined stability of times past calls us to seize them in memory like a low hanging branch over the swiftly flowing current of time. People facing the fact of impending death go through a series of stages, of which initial denial of the reality is the first. The way we talk creates an illusion that works for a time. We may persuade ourselves for a while that we're not really going to die.
Denial fails, of course.
When disease progresses to a point where illusion finally doesn't mesh with reality, other defenses come into play. We cannot change what happens with aging or death, but we can comfort ourselves by the way we talk about it to ourselves, and the words become the greater reality for a while. It is also true that the way we talk to ourselves can be enormously therapeutic. If, as a result of our experience, we arrive at a new synthesis that helps us adjust better to aversive external realities, subjective reality can be profoundly altered for the better. If we have experiences of a kind that persuade us that biological death is only a transition and not the end of existence, we gain hope that diminishes fear and carries us through.