“Whenever you suffer pain, keep in mind that it’s nothing to be ashamed of and that it can’t degrade your guiding intelligence, nor keep it from acting rationally and for the common good. And in most cases you should be helped by the saying of Epicurus, that pain is never unbearable or unending, so you can remember these limits and not add to them in your imagination. Remember too that many common annoyances are pain in disguise, such as sleepiness, fever and loss of appetite. When they start to get you down, tell yourself you are giving in to pain.”
Marcus Aurelius, Meditations, 7.64