No Nostalgia?

I have often wondered why I tend to feel far less nostalgic than most people around me.
When I went to college, I did not miss school or home as much as some of my peers seemed to. When I went abroad to work on my PhD I did not miss my country or hometown a great deal, and I am almost sure that when I leave my current university town in the US, I will not regret it much. I do not particularly miss old friends, never really mull over memories fondly stashed away in some well-lighted recess of the mind; to be lovingly brought out, dusted, caressed and stowed away again for future moments of  idle indulgence. For though the Greek roots and the dictionary definition of "nostalgia" imply pain ( Gk. "algos" = pain), this is a mildly pleasurable and therefore desirable sort of pain for most. This is as it were an imagined sense of well-being associated with some arbitrary point of time in the past, which probably also serves as some psychological defence mechanism - a sort of selective filtering of memories that helps us forget painful moments in the past while also letting us hope for a more pleasant future by association (i.e we were once better off than we are now, and so there must certainly exist better things to aspire or look forward to).  Not to belittle it, but this is about all the merit I can see in nostalgia.

My  near total lack of nostalgia has often troubled me. As I see it, there could be two major factors at work behind this, and neither is very comforting.  I could be this thoroughly unromantic, even near-emotionless pragmatist that does not see much point in idle rumination. Or is it possible that there are very few pleasant  memories worth recollecting in my past life?  Neither is a very comforting thought. I have almost ruled out the first reason - I am certainly not heartless or unsentimental. I would be very happy to see an old friend after many years for example.  I certainly romanticize a lot when it comes to future possibilites. The second question is somewhat relative - I certainly don't think my childhood or past have been singularly unhappy in the conventional sense.

After a good deal of introspection (something I am prone to doing obsessively) I have isolated a few possible causes for my lack of nostalgia. The easiest to state would be my better-than-average memory. A number of people who have met/known me have testified to this - I tend to remember details very well. I have a natural love for information - I like to hoard  little tidbits that people usually discard from the attics of their minds.  As such, viewing my past with rose-tinted glasses and filtering out the bad memories, is hard for me. People are in a position to romanticize only when the circumstances seem remote - with me little seems remote - I tend to remember nitty-gritties very vividly even after years.  I cannot delude myself into believing that  my past was significantly happier than my present.  Too much memory can be a confusing and painful matter too. For then the person tends to be plagued by the worse memories.  To cope with this, I think I have developed a defence mechanism where I try not to dwell too much on the past - I have developed this aversion for too much memory - which is why I have trained myself to pay as little conscious attention to memories as possible.  There's a more specific reason when it comes to memories of places and people. When I see people growing nostalgic over their old school photo showing them participating in some group activity with their classmates, I realize that I have always been a loner and rarely been part of community activities with great enthusiasm.  The people who seem to miss school most were the ones who were the most active and outgoing at school - those who participated the most in school activities, those who formed large groups and defined their own subculture, the students who organized and performed in and won prizes in the college fest - the more vociferous and more prominent ones that had their say in matters, the more popular and confident and talented types. I have often preferred to keep to myself, keeping whatever little talent I may have had well-concealed or low key, and the idea of being part of  a group has always been somewhat unattractive to me.  When I look at old albums or yearbooks I very rarely find myself in the group photos. I hardly spoke the common lingo in school or college. My oddity has always been very precious to me. This is why I find it hard to be loyal to institutions. I'd like to believe that to a large extent I am self-taught and the institution can't claim much credit to what I am now today, because the institution's role has been very superficial.  Thus not being a part of it all, the frigid distance , has given me the honest unclouded perspective that precludes the necessity of  nostalgia. Perhaps indeed, my youth has been less happy than those bright-eyed souls who had more vigorous experiences and memories to draw from, which thus endowed them with a greater sense of belonging that they now miss on occasions.