My father, non-local boy from Tacoma, Washington, went with my local NYC mother in the subway and held the door open at some entrance, waiting for someone else to take it from him. My mother had kept walking and saw he wasn't with her, ran back to find him, still holding the door. She told him to just let it go. He said it will hit someone, she said just LET IT GO...his natural good manners did not work in NYC. He finally let go, no one got smashed in the face (probably no one said thank you either). In some busy situations (subway at rush hour) it's a little more "every man for himself..." And this was back in the 1950's when, arguably, even NYC was more polite...