When did anger, however, ever teach someone to play music or pilot a ship? - Epictetus

So decide now that you are worthy of living as a full-grown man who is making progress, and make everything that seems best be a law that you cannot go against. And if you meet with any hardship or anything pleasant or reputable or disreputable, then remember that the contest is now and the Olympic games are now and you cannot put things off any more and that your progress is made or destroyed by a single day and a single action

When you are alone, you should call this tranquility and freedom and when you are with many you shouldn’t call this a crowd, or trouble or uneasiness but festival and company and contentedly accept it.

If you want not just peace and contentment, but power and wealth too, you may forfeit the former in seeking the latter, and will lose your freedom and happiness along the way. Whenever distress or displeasure arises in your mind, remind yourself, “This is only my interpretation, not reality itself.” Then ask whether it falls within or outside your sphere of power. And, if it is beyond your power to control, let it go.