Nostalgia is often defied as a state of being homesick, or the sentimentality of the past.
One immediate way of considering nostalgia is through personal and individual experiences. It could be triggered in many ways, through visuals, smell, taste, touch and so on. Effectively anything that is strongly bounded to a memory in ones’ mind and it brings that memory back. Another aspect of nostalgia could be considered as cultural and collective, as a specifically targeted group of people.
Can nostalgia be destructive?
“Past events exist, after all, only in memory, which is form of imagination.’ (Le Guin 2001, no pag.) The theory of truth is very subjective itself; it is seen differently by any individual, therefore the memory of past, even historical events, can be only a romanticised interpretation of the incident. Nostalgic approach to occurrences can really alter your perspective and very much idealised the episodes. It makes us looking at world through rose-tinted glasses that distorts the present and compare it to the best, often non-existing, past.
According to Kohn nostalgia is promoting only selective memory and possibly a misrecognition of the past. In that sense nostalgia brings many problems of different nature to the table.
(If nostalgia can be destructive it can also conker and brings together the identity and heritage.)