I've not heard of Grand Isnalnd. Long Island, yes, and I have a sister there.
You seem to have traveled more around that area than I did. I did graduate from high there in Manhattan long ago. Much later, I remember going to Manhattan with my daughters to visit the doll Store, American Girl. They loved going there. That's about the last memory I have of NY, besides going out to see my sister. And i agree, NYer's are very friendly, as much as others try to portray them being rude. I have seen ruder people in NJ, honestly. Here in Ohio they are super sweet and helpful, for the most part. :)