Internal Retreats [Marcus Aurelius, Meditations]

Men seek retreats for themselves - in the country, by the sea, in the hills - and you yourself are particularly prone to this yearning. But all this is quite unphilosophic, when it is open to you, at any time you want, to retreat into yourself. No retreat offers someone more quiet and relaxation than that into his own mind, especially if he can dip into thoughts there which put him at immediate ease: and by ease I simply mean a well-ordered life. So constantly give yourself this retreat, and renew yourself. The doctrines you will visit there should be few and fundamental, sufficient at one meeting to wash away all your pain and send you back free of resentment at what you must rejoin

Finally, then, remember this retreat into your own little territory within yourself. Above all, no agonies, no tensions. Be your own master, and look at things as a man, as a human being, as a citizen, as a mortal creature. And here are two of the most immediately useful thoughts you will dip into. First that /things/ cannot touch the mind: they are external and inert; anxieties can only come from your internal judgement. Second, that all these things you see will change almost as you look at them, and then will be no more. Constantly bring to mind all that you yourself have already seen changed. The universe is change: life is judgement.