The Golden Rule (n.):

1. a rule of ethical conduct, usually phrased, "do unto others as you would have them do unto you," or, as in the Sermon on the Mount, "whatsoever ye would that men should do to you, do ye even so unto them." Matt 7:12, Luke 6:31

Be kind to everyone, don't be quick to judge, and don't assume anything about anyone's situation. There is no way for us to know what the lives of the strangers standing next to us on the street have been like that day. We never know if the bank teller, barista, or customer service representative that we are giving a hard time has reached their breaking point. We never know whether our insults (however concealed or little that they may be) will be that one thing that pushes that person over the edge. You never know if the person serving you your dinner has had a bad night... if they've been shorted cash by their previous tables, if they've dealt with rude customers all day, if they are fighting to make rent, if someone close to them has just died. Never just assume that the look of sadness or frustration in their eyes is a part of their character, and not just their circumstances. We need to stop being so offended; stop taking everything so personally. We need to stop approaching this life with the thought "how can I get more for less?" and instead approach it with the question "what can I do to help someone out today?" We just need to slow down, and take a minute to notice a small detail of someone else's life, and maybe, just maybe, completely turn their day around.