Guilt is one of the most unpleasant emotions that exists, in my opinion. I hate, hate, hate the thought of my presence or actions harming anybody. I like to think that overall the world is a better place for my having been in it. I try to avoid having to feel guilt as much as possible by trying to be as good a person as I can be. That makes my actions sound a lot more selfish than altruistic, huh? Physically, it affects me by making my stomach feel like it weighs about 100 pounds. Old guilt fades, but I can still feel it strongly if I think too much about past events. I can absolve it a lot more by acting to correct my mistake, or at least doing some nice things for the person I have wronged. I always want to have helped any given person more than I have harmed them, in my life. I guess I define guilt as a negative emotion resulting from having brought harm to another entity. Goes hand-in-hand with regret.