From: The Golden Sayings of Epictetus (translated by Hastings Crossley) - from Project Gutenberg.
Asked, Who is the rich man? Epictetus replied, "He who is content."
It is hard to combine and unite these two qualities, the carefulness of one who is affected by circumstances, and the intrepidity of one who heeds them not. But it is not impossible: else were happiness also impossible. We should act as we do in seafaring.
"What can I do?"—Choose the master, the crew, the day, the opportunity. Then comes a sudden storm. What matters it to me? my part has been fully done. The matter is in the hands of another—the Master of the ship. The ship is foundering. What then have I to do? I do the only thing that remains to me—to be drowned without fear, without a cry, without upbraiding God, but knowing that what has been born must likewise perish. For I am not Eternity, but a human being—a part of the whole, as an hour is part of the day. I must come like the hour, and like the hour must pass!