Difficulties are things that show a person what they are. - Epictetus

The chief task in life is simply this: to identify and separate matters so that I can say clearly to myself which are externals not under my control, and which have to do with the choices I actually control. Where then do I look for good and evil? Not to uncontrollable externals, but within myself to the choices that are my own...

Whatever moral rules you have deliberately proposed to yourself. abide by them as they were laws, and as if you would be guilty of impiety by violating any of them. Don’t regard what anyone says of you, for this, after all, is no concern of yours.

Remember that it is not he who gives abuse or blows who affronts, but the view we take of these things as insulting. When, therefore, any one provokes you, be assured that it is your own opinion which provokes you. (20).