Flags. I was in NY in 2002 when 9/11 was on everyone’s mind and in every conversation.
Now it’s not so omnipresent and genuinely, I have to say, people here are Nice. Twice bus drivers have gone out of the way to chat and have thanked me for visiting(!), people on the subways are open for questions and will happily give you advice, and on the street they are Glad to point you in the right direction and then they encourage you to have a nice day. It’s true.