^^ True. And on the Underground, the onlookers knew that you were the kind of person who offers his seat to a lady. They also know that the lady in question, repays kindness with abuse. Sounds like you came out looking pretty good. Opening doors, "Merry Xmas", etc. ..., don't let the people who repay small kindnesses with abuse keep you from offering small kindnesses.
i still hold doors, cary bags, and offer seats, and will continue to do so.. its just something i consider the correct respectable thing to do, and besides, with the large quantity of arseholes around these days, i sometimes think its nice for people to see there are still people around that do care, and do understand respect..