A personal principle may have started as a defense against one particular person.

Principles often have a biography. You decided never to depend on anyone, or always to say what you think, and the decision was made against one particular person in one particular period. It then generalised into a rule for everybody, including people who were never that person and never will be.

Take one of your firm principles and try to find its first occasion. If there is one, ask whether the rule still fits situations that do not resemble it. Keeping the lesson and dropping the blanket application is usually available.