You scratch my back, I'll let you listen in on my break-up

There was one afternoon last summer when I was on the phone with my sister and I realized 1) I was beginning to run late for a job interview, and 2) I didn't have any nylons to wear to this interview. My sister suggested that I buy a pair at the drug store and put them on while I was waiting for the subway, she said she was certain that New Yorkers had seen far stranger things on the subway platforms before and that I would go unnoticed by most. While inevitably I bought the nylons and put them on in the office bathroom before the interview I began to notice the things people do both on the subway platform and on the trains themselves.
New York City has a fascinating culture to it. Partly what adds to this is the fact that there are upwards of 8 million people existing together in one relatively small city while trying desperately to pretend they are completely alone. Truthfully it seems this is the only way to make it through the day in a city so over-crowded with residents, blow ins, day trippers, and tourists. Likewise it appears to be the only way to function on a subway platform or in a train car, when your forced to sit or stand at any given hour of the day with your knees pressed into the calves of an individual whose intimate space you've necessarily been introduced into though you may not even know what their face looks like, let alone what their name is. Its easy to see why this set up might lead to a small amount of depersonalization and lead to some of the more, well, quirky and private behaviors people partake in within these most public of spaces.
I can remember one instance when I was coming home from the far reaches of Harlem to the even further reaches of Brooklyn, and I was standing grasping the subway pole, rather exhausted from a painfully long day. This woman with a stroller entered the car somewhere around 14th St. and stood hanging on to the pole that runs beside the door as there were no seats available. Anyway, at some point in our ride we stalled over the Manhattan bridge and I can vaguely recall the woman shifting to my pole. In no time at all she was standing with her back to my poll as occasionally people are wont to do when the pole is empty and no one else is using it- this however, what not the case for my pole, but nonetheless this is what she did. Now typically when people make the move to rest their backs on a pole in use, they make an effort to keep their back away from the hand of the pre-existing pole inhabitant- not this woman. As time progressed and we remained stalled the woman began to use my knuckles, which were facing outward in her direction, as a means to either scratch or massage her back, and continued to do so, rather aggressively, until we reached my final destination at which point I pulled my hand out from behind her rather concerted efforts at relief and walked out of the train. (I will leave why I didn't move my hand up to your own interpretation- it wasn't that interesting a reason anyway).
Beyond the physical contact though, individuals will often be found doing numerous other tasks or engaging in behaviors you may not, imagine typically occurring in a subway station or car. Heres a small list: changing clothes, talking/laughing/arguing to themselves- loudly, applying their make up, curling their hair, praying aloud, reading aloud from the bible/quarran/torah/ copy of Dyanetics, singing operatic compositions for no money or audience, blowing their noses into trash cans, peeing in direct view of others, engaging in heated debates and breakups on their cell phones, writing love letters, studying for immigration exams, studying for neurology exams, studying for GED exams, making out, having sex, threatening their children, practicing dance moves, falling asleep on another person (usually a stranger), shadow boxing, and rearranging the "wet paint" signs so they say "aint wet". Some of the things on this list I'm sure you could imagine more than others, and yet the extent of what people might do in those public spaces certainly doesn't end there.
So what is it about this city that people feel either so completely at home or completely alone that they feel safe to engage in any number of things outside that they might normally keep private? Could it be that the boundaries of individuals who live crushed among 7,999,999 other people tend to get crushed as well? Or is it more that you figure among so many others you get lost in the crowd and no one notices that you're putting on a pair of pants underneath your skirt and slipping the skirt off over those pants?
Have we depersonalized so much in this city that we treat other individuals- other human beings, as walls, mirrors, polls, pillows, and back-scratchers? And above all that, is this a bad thing or is it simply a way coping or a way of being close while distant, a way of making this city seem a little more personal and inviting- a little more like home…
I don't know for sure- but I think that strange as it is, perhaps that's one of the things that makes New York so inclusive, such a sought after place, and so intriguing to so many ---well that and its enormous buildings and the ability to get breakfast/drugs/sex delivered to your house from the local bagel shop or diner, but thats a whole other facet to the culture of New York that I'll save for another time.