Conscience

That small voice that tells you if what you are doing is right or wrong is your conscience. If it also argues with you and suggests bizarre or dangerous actions, that's a schizophrenic personality disorder and you have more to worry about than a happiness deficiency.

If you habitually act in a way you believe you shouldn't, you can imagine the effect that will have on your sense of self worth. There is also the chance you are behaving pretty badly and the worry that your actions might catch up with you won't help you sleep nights either.