It is not just chivalry but courtesy to our fellow man that is dead. We all need to relax , let people in during comutes, open doors for both sexes its just polite.Obviously coomon sense should enter into it like you dont stop traffic to let one car in or create line ups opening doors but we could all stand to be more at ease with each other. What helps me is when I let someone in or open a door for them and they dont respond is waving at them or the your welcime tactic mentioned above, but mentally I just think to my self that this person is lost in there own crappy existance and I just pity them instaed of getting angry like I used to . Just my opinion hope it helps.