Here's an odd culture shock I've noticed since moving to New Jersey.
In Indiana, it's actually rather customary to make eye contact when you walk past someone, even to say "hello" or "how's it going?"
Here (New Jersey), you do not make eye contact with someone you don't know and aren't interacting with. You sure as hell don't say "hi." It's an invitation for begging, or worse. Not that you'll get that every time, but people here are very touchy about it. It's been a hard habit to break, because I feel like a bad person if I don't acknowledge the presence of someone walking past me. But you're just supposed to keep your eyes cast down and avoid running into people. Other than that, you don't interact with Joe Blow on the street.
Yeah, I had a similar experience. I grew up in Oregon and lived there until I was 25. People are relatively open and friendly and it was much more common than not to make eye contact and say hello to people there. Then I moved to Boston.

Like you say, the "rule" is that you don't make eye contact and you do not speak to people you don't know, unless you absolutely positively have to ... for instance to say, "Excuse me, I don't mean to intrude, but I thought you might want to know that your hair's on fire."

And the whole "no talking in the elevator" thing -- which I have been informed is a "universal rule" in this part of the country -- is still just bizarre to me. I mean, I can sort of -- sort of -- understand not speaking to people you don't know in an elevator, though it seems odd to me when it's the elevator in my office building and it's people I've seen every day for something like 7 years now. But, hey, it's "the rule." What I find really odd, though, is when I'm waiting for the elevator with someone I do know, chatting with them, and they clam up as soon as we step in that little box and act like I don't exist. Then, when the doors open, the conversation can continue. I mean ....
