[Nostalgia] defuses what could be a powerful panic-prone reactivity to jarring change and uncertainty by turning it into tender musing and mutually appreciative self-regard over a shared-past. To the extent that constant change, at all levels and in all realms of social life, seems to be endemic to modern civilization, some such ‘outlet’ or ‘safety valve’ may be required….This allows time for needed change to be assimilated while giving the appearance, as nostalgia does, of meaningful links to the past.