Epictetus

Epictetus (circa 55-135 CE) taught in Rome until the year 94 CE, when the Emperor banished all philosophers from the city. He kept teaching in exile, one of his notable students being Marcus Aurelius. This is an excerpt from The Art of Living: the Classical Manual on Virtue, Happiness, and Effectiveness. (Interpretation by Sharon Lebell).

Happiness Can Only Be Found Within

Freedom is the only worthy goal in life. It is won by disregarding things that lie beyond our control. We cannot have a light heart if our minds are a woeful cauldron of fear and ambition.

Do you wish to be invincible? Then don't enter into combat with what you have no real control over. 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.

Authentic happiness is always independent of external conditions. Vigilantly practice indifference to external conditions. Your happiness can only be found within.

Stop aspiring to be anyone other than your own best self; for that does fall within your control.

Hmmm, could have been written today.