I've lived in my house for one year. It's a very modest house in a very modest neighborhood. I know all of the neighbors on my block, and quite a few others by site if not name in the neighborhood. I'm not a very gregarious person, but having a dog and walking through the neighborhood twice a day as we do makes us a familiar sight. I've also been named the president of our civic association, so I kinda have to get out and meet people. I see it as an opportunity to overcome my natural shyness while hopefully helping improve the neighborhood in a few key ways (cleaning up trash, reducing crime, addressing illegal pit bull breeding, and getting a garden club going come to mind).

When I lived in Paris, however, I was quite content to NOT know the other people in my apartment building. Since we lived in such close quarters, it was best to not know each other very well. That's pretty common, at least in my experience in apartments.