Epictetus
1. If you would be outraged if someone tried to take control of your body, then why do you allow anyone to control your thoughts and judgments? You let others shake your beliefs and make you doubt without feeling offended or humiliated.
2. Don’t expect events to happen as you wish; instead, train yourself to want everything to happen exactly as it does, and you will be happy.
3. If a desirable object or fantasy disturbs your mind, remind yourself: “You are just a thought, a potential future, not a reality, no matter how much you seem like one.” Then test this thought against your principles: first, determine if the realization of this desire depends solely on you. If it does not, be ready to say, “This does not concern me.”
4. Train yourself to observe what you desire and what you fear, but do so with ease, without force or excessive effort. Every person is a slave to anyone who can give or take away something they desire or fear.
5. The attitude and character of the ordinary person: they expect neither good nor bad from themselves and rely entirely on external circumstances. The attitude and character of a philosopher: they expect everything—both good and bad—from themselves alone.
(c) Epictetus