I guess it depends on what you define as a principle. You are in a manner correct, but saying that "nobody stands by their principles" is not nuanced enough. I

I guess it depends on what you define as a principle. You are in a manner correct, but saying that "nobody stands by their principles" is not nuanced enough. I personally would broaden the definition that a principle depends on the context, and in the simplest sense a principle has to work in your favor in the long run. For example honestly is generally a good policy, but not if you are a Jew trying to hide your ethnicity in Nazi Germany.