What no one tells you about NY is that there is no way to escape the reality of other people.
The thing about living in California, or probably any suburb, exurb or rural area in the US, is that you can avoid other people, except those you choose to let into your life. Most of them just float by, hermetically sealed into cars, and so you never have to acknowledge that they are, in fact, human. Or you float by, hermetically sealed into your car, so fast that you can pretend there are no humans in other cars or buildings. You may zoom past the occasional pedestrian, but it happens in such a blur that they seem more like mannequins than people.
But in Manhattan, you are literally elbow to elbow with other human beings the minute you step out your front door. Sixty or so human beings are on that subway car with you, and another few thousand at the museum, not to mention the hundreds you pass as you walk. Behind every lighted window, behind every shop door, there are human beings with hopes, dreams, fears, neuroses, friends, skills, talents, ambitions, proclivities -- each human a universe unto herself.
It makes me very curious -- and a bit overwhelmed.