A passage from Marcus Aurelius
Marcus Aurelius, Meditations 12.3
✱
Forget everything else. Keep hold of this alone and remember it: each of us lives only now, this brief instant. The rest has been lived already, or is impossible to see.
Related passages
✱
Men seek retreats for themselves, houses in the country, sea-shores, and mountains... But this is altogether a mark of the most common sort of men, for it is in thy power whenever thou shalt choose to retire into thyself.
✱
At dawn, when you have trouble getting out of bed, tell yourself: 'I have to go to work — as a human being.'
✱
Everything you're trying to reach — by taking the long way round — you could have right now, this moment. If you'd only stop thwarting your own attempts.