It comes as no surprise that it is the unchanged and unchangeable aspect of something which brings on feelings of nostalgia. In a world that moves quickly, inevitably so for someone who is able to read this, an encounter with something (the trigger of nostalgia) which has stayed the same from long ago, re-affirms our sense of continuity with ourselves. Through what is probably an evolutionary trait of being engaged with the present, fully conscious and ready for the World, our access to memories hosting our nostalgia is somewhat limited to the more inactive corner of our brains, triggered only by a specific instance. The fact that feelings of nostalgia consist of retained memories or feelings often of no specific time and place, with nostalgia itself being the only function it actually serves, I think, shows why, historically, nostalgia is sometimes viewed with a slight distaste on the grounds of self-indulgence, time wasting or even depression. This has been evident in reactionary responses to the melancholy of soldiers and sailors of the past – ‘a strange sickness’ was often the explanation, so vague was (and is) the idea. When it is sometimes noted that people are ‘living in the past’, nostalgia permits exactly this, albeit for a short period of time (which is why ‘pang’ is a useful descriptive word when the onset of nostalgia presents itself). As one would not be able to experience the initial sensation again (which they were having nostalgia about) in the first place unless they were somewhere or someone far removed from the individual who had this initial sensation (and we must know this at the time, even if we are not directly aware of it, or else there is no continuity with the self and nostalgia would be a different feeling entirely), nostalgia is the ultimate bittersweet sensation as we reconcile our past with the present.
It is curious that the feeling of nostalgia is so closely entwined with a time when we were much younger. We are almost certainly basking in the sweetness of pure innocence when we feel nostalgia for our youth – certain songs, in particular remind me of a place where my word-view was so completely overwhelmingly simple and different to one I possess now and remembering this is somehow, pleasing and somber. This is the realisation of change; which on reflection might seem to explain why we view our past through nostalgia with a shade of melancholic warmth; it is unique to us and for whatever reason that feeling or memory stayed with us, (something we are normally unaware of – it is only on reflection we realise that long-forgotten things have actually been retained), and we recognise what we used to be, or have, creating a paradoxical sadness. The emotional equivalent perhaps of being tickled, one is not sure whether we are experiencing pain, or pleasure or something in between. When they say you have your ‘life review’ before death, one is tempted to think it is feelings of this nature which will be recalled. Intoxicating might be the descriptive word for a ‘pang of the past’ and it is easy to see how someone might get lost in nostalgia, perhaps for reasons of regret;they intoxicate themselves (e.g. perhaps a widow hearing her deceased partners favourite song), yet somehow it still seems a pitiful way to stay content. The nature of nostalgia allows for it to work best when it is only an occasional occurrence, so overwhelming can be the feeling, allowing for the pungency to wear off after a period.
The gentle surprise of nostalgia to me seems to reaffirm ourselves with who we once were, along with a deep seated longing; this, a mystery which hangs on the periphery of the phenomenon of consciousness.