One that desires to excel should endeavor in those things that are in themselves most excellent.
EpictetusAuthentic happiness is always independent of external conditions. Vigilantly practice polite indifference to that which we can't control. Your happiness can only be found within.
EpictetusIf you want to improve, be content to be thought foolish and stupid with regard to external things. Don't wish to be thought to know anything; and even if you appear to be somebody important to others, distrust yourself. For, it is difficult to both keep your faculty of choice in a state conformable to nature, and at the same time acquire external things. But while you are careful about the one, you must of necessity neglect the other
Epictetus