People who know themselves deeply become harder to insult inaccurately.

An insult only lands when it touches something unsettled. If you have looked at yourself honestly, most attacks either describe something you already know and have made peace with, or they describe someone who is not you. Either way there is nothing for the words to grip. What remains is a comment about the person saying it.

When something stings unexpectedly, treat that as a place worth examining rather than as an injury to avenge. The sting is usually pointing at a question you have not answered for yourself yet. Answer it, and the same words stop working.