Politeness is okay, but it gets old and boring. You want to attack life with a passion, not a politeness, you want people to think about you and remember you and say "she is so passionate" you don't want people to think about you and remember you and say "she is so polite," because, who cares about polite?
A moment of truth is very powerful. Instead of smiling to be polite, just frown. Instead of laughing when you are nervous or uncomfortable, just speak your truth. Instead of acting like everything is all right, proclaim it isn't alright, and talk about your feelings! Honor your truth. Honor yourself. Be real.