Begin the morning by saying to thyself, I shall meet with the busy-body, the ungrateful, arrogant, deceitful, envious, unsocial.

You know people with these tendencies exist. You know you encounter them on a regular basis. You know you sometimes suffer the same flaws. It is important to recognize that interacting with these people is not just inevitable but in many cases essential for getting through your day. Recognize that people have these flaws and be cordial with them. Also know that because you will encounter these people, allowing the interaction to own your emotions causes unnecessary suffering in your life.

This quote also sums up Stocism pretty well through the lens of interaction with others. Things that are not within your power to control should not be within the power to control you. Set yourself up for success each day by recognizing the world as it is and navigate through it.