What upsets people is not things themselves but their judgments about these things.Take the insults of your fellow humans to be like the barking of a dog. When a dog barks, you might make a mental note that the dog appears to dislike you, but you would be a fool to become upset by this fact.
Consider the source of an insult. If you respect the source and value his opinions, then his critical remarks shouldn’t upset you. However, if you don’t respect the source of an insult, rather than feeling hurt by his insults, you should feel relieved.
Advice… just refuse to respond to an insult, it is one of the most effective responses.
Taken from sivers.org/book Notes from – William Irvine’s A Guide to the Good Life: The Ancient Art of Stoic Joy