My principles are probably stupid to most people but whether they be right, wrong or neutral, I believe in sticking to what you believe in despite the impact it may or may not have. I generally do not watch horror movies because I don't like people being evil for the sake of evil however, something about characters like Javier Bardem played in No Country For Old Men (I know it's not a horror film) do not bother me. Yes, they are doing evil things but it's based on a principle not random choices. Emotions are what make us human but it is principles that are needed as a check and balance against those emotions. Most people who are professional card players or stock traders will tell you that they have a set of guidelines they follow and when they don't, that's when they fuck up.
You can change what you believe as time wears on and you see things differently because of experiences that you have but if you have some principles, if nothing else, hold them sacred because otherwise we are left with varying stages of chaos.