Meditations 7.58

In everything which happens keep before thy eyes those to whom the same things happened, and how they were vexed, and treated them as strange things, and found fault with them: and now where are they? Nowhere. Why then dost thou too choose to act in the same way? and why dost thou not leave these agitations which are foreign to nature to those who cause them and those who are moved by them; and why art thou not altogether intent upon the right way of making use of the things which happen to thee? For then thou wilt use them well, and they will be a material for thee [to work on]. Only attend to thyself, and resolve to be a good man in every act which thou doest: and remember...

Marcus Aurelius, Meditations 7.58, translated by George Long

In every contingency keep before thine eyes those who, when these same things befell them, were straightway aggrieved, estranged, rebellious. Where are they now? Nowhere! What then? Wouldst thou be like them? Why not leave those alien deflections to what deflects and is deflected by them, and devote thyself wholly to the question how to turn these contingencies to the best advantage? For then wilt thou make a noble use of them, and they shall be thy raw material. Only in thought and will take heed to be beautiful to thyself in all that thou doest. And remember, in rejecting the one and using the other, that the thing which matters is the aim of the action.

Marcus Aurelius, Meditations 7.58, translated by C. R. Haines