On being who you want to be

"Lay down from this moment a certain character and pattern of behavior for yourself, which you are to preserve both when you're alone and when you're with others." - Epictetus, Handbook

In other words, practice constantly being the person you want to be. This quote compliments nicely the passage in Discourses where Epictetus tells his students to decide first what kind of person they want to be, then to ensure that all of their actions are consistent with that goal.

You can also see echoes of this teaching in Meditations, where Marcus Aurelius tells himself to think only thoughts that he would not hesitate to share with others if asked:

You need to avoid certain things in your train of thought: everything random, everything irrelevant. And certainly everything self-important or malicious. You need to get used to winnowing your thoughts, so that if anyone says, "What are you thinking about?" you can respond at once (and truthfully) that you are thinking this or thinking that. And it would be obvious at once from your answer that your thoughts were straightforward and considerate ones - the thoughts of an unselfish person, one unconcerned with pleasure and with sensual indulgence generally, with squabbling, with slander and envy, or anything you'd be ashamed to be caught thinking.

Aurelius says that someone who is able to maintain their inner self always would be "an athlete in the greatest of all contests - the struggle not to be overwhelmed by anything that happens."