When you relax your attention for a little, do not imagine that you will recover it wherever you wish, but bear this well in mind, that your error of today must of necessity put you in a worse position for other occasions.
AI put this 1916 translation into today's English. Only the wording changed: each rewrite was checked against the original to keep its exact meaning.
Original translation
“When you relax your attention for a little, do not imagine that you will recover it wherever you wish, but bear this well in mind, that your error of to-day must of necessity put you in a worse position for other occasions.”
“It is the act of an ill-instructed man to blame others for his own bad condition; it is the act of one who has begun to be instructed, to lay the blame on himself; and of one whose instruction is completed, neither to blame another, nor himself.”
“Remember that it is not the person who insults you or strikes you who offends you, but your opinion about these things as being offensive. When a man then irritates you, you must know that it is your own opinion which has irritated you.”
AI put this 1877 translation into today's English. Only the wording changed: each rewrite was checked against the original to keep its exact meaning.
Original translation
“Remember that it is not he who reviles you or strikes you, who insults you, but it is your opinion about these things as being insulting. When then a man irritates you, you must know that it is your own opinion which has irritated you.”
Translated by George Long, 1877
“The condition and characteristic of an uninstructed person is this: he never expects from himself profit (advantage) nor harm, but from externals. The condition and characteristic of a philosopher is this: he expects all advantage and all harm from himself.”
― EpictetusDiscourses (Book IV, Chapter 12)