In New York when you say “Gut Shabbos” to people they look you up and down and wonder “Do I know who that is” and wonder why I said Gut Shabbos to them…
Funny you should mention that. When my wife (who lived in Flatbush at the time) and I were newly engaged, we were crossing Ocean Parkway one Shabbat afternoon when an unknown man came towards us and said “Good Shabbos and mazal tov!” Taken aback that a stranger would wish us mazal tov, I asked, “Do I know you?” He peered at us for a moment and said, “Sorry, I thought you were someone else.”