You can always be content if you continue to make good progress. - Marcus Aurelius

In a sense, people are our proper occupation. Our job is to do them good and put up with them. But when they obstruct our proper tasks, they become irrelevant to us--like sun, wind, and animals. Our actions may be impeded by them, but there can be no impeding our intentions or our dispositions. Because we can accommodate and adapt. The mind adapts and converts to its own purposes the obstacle to our acting. The impediment to action advances action. What stands in the way becomes the way. (Hays translation)

Be tolerant with others and strict with yourself.

You see how few things you have to do to live a satisfying and reverent life? If you can manage this, that's all even the gods can ask of you. (Hays translation)