Simon

“Remember, it is not enough to be hit or insulted to be harmed, you must believe that you are being harmed. If someone succeeds in provoking you, realize that your mind is complicit in the provocation. Which is why it is essential that we not respond impulsively to impressions; take a moment before reacting, and you will find it easier to maintain control.”
― Epictetus, The Art of Living: The Classical Manual on Virtue, Happiness and Effectiveness

“Your happiness depends on three things, all of which are within your power: your will, your ideas concerning the events in which you are involved, and the use you make of your ideas.”
― Epictetus, The Art of Living: The Classical Manual on Virtue, Happiness, and Effectiveness

“You become what you give your attention to.”
― Epictetus, The Art of Living: The Classical Manual on Virtue, Happiness and Effectiveness

“No one could endure lasting adversity if it continued to have the same force as when it first hit us. We are all tied to Fortune, some by a loose and golden chain, and others by a tight one of baser metal: but what does it matter? We are all held in the same captivity, and those who have bound others are themselves in bonds - unless you think perhaps that the left-hand chain is lighter. One man is bound by high office, another by wealth; good birth weighs down some, and a humble origin others; some bow under the rule of other men and some under their own; some are restricted to one place by exile, others by priesthoods: all life is a servitude.

So you have to get used to your circumstances, complain about them as little as possible, and grasp whatever advantage they have to offer: no condition is so bitter that a stable mind cannot find some consolation in it.”
― Seneca, On the Shortness of Life: Life Is Long if You Know How to Use It