If you want to be steady
“The essence of good is a certain kind of reasoned choice; just as the essence of evil is another kind. What about externals, then? They are only the raw material for our reasoned choice, which finds its own good or evil working with them. How will it find the good? Not by marveling at the material! For if judgements about the material are straight that makes the choices good, but if the judgements are twisted, our choices turn bad.”
— Epictetus, Discourses, 1.29.1-3
People, situations, objects, and other things outside your control are neither good nor evil. It is the choices you make upon those that you alone can judge to be good or bad.
This maps closely to a mantra I have been trying to follow during the last couple years,’do only what you can be proud of’. While my focus has been on co-parenting choices and divorce issues – choosing what to fight and and what to let wash by. I can see how it applies to a lot more of life.