Epictetus - On Attention and Maxims

"Do not seek happiness outside, but within yourself, otherwise you will never find it..." (Epictetus).
Epictetus (Greek: Επίκτητος; romaniz.: Epíktetos; Hierapolis, 55 - Nicopolis, 135) was a Greek stoic philosopher who lived most of his life in Rome, as a slave in the service of Epaphroditus, Nero's cruel secretary who, according to tradition, once broke his leg.
Despite his condition, he managed to attend the lectures of the famous stoic Gaius Musonius Rufus. Of his work are preserved the Encheiridion of Epictet (also known as Epictet's Manual) and the Diatribes (or Discourses), both edited by his disciple Lucius Flavius Arrian of Nicomedia.
How to live a full life, a happy life? How to be a person with good moral qualities? Answering these two fundamental questions was Epictetus' sole passion. Although his works are less known today, due to the decline of classical culture teaching, they had enormous influence on the ideas of the leading thinkers of the art of living for almost two thousand years.
For Epictetus, a happy life and a virtuous life are synonymous. Happiness and self-fulfillment are the natural consequences of right attitudes.
In Nietzsche, Epictetus is linked to individualism, so that Nietzsche sees in Epictetus therefore a contrast to the current morality linked to the collective and the social.
Citations
"Of the things that exist, some are our burden; others are not. Our burden is our judgment, our impulse, our desire, our repulsion - in short: everything that is our action. Not our burden is the body, possessions, reputation, public offices - in short: everything that is not our action. By nature, the things that are our burdens are free, unobstructed, unhindered. Those things that are not our burden are weak, slaves, obstructed, of another.
"If someone tells you that a certain person speaks badly about you, don't justify yourself about what is said about, but answer, 'He ignores my other faults, otherwise he wouldn't have mentioned just those.'"