Imperator Caesar Marcus Aurelius Antoninus Augustus (April 26, 121 March 17, 180) was Roman Emperor from 161 to his death in 180. He was born Marcus Annius Catilius Severus, and at marriage took the name Marcus Annius Verus. ...
Observe constantly that all things take place by change, and accustom thyself to consider that the nature of the Universe loves nothing so much as to change the things which are, and to make new things like them.
Always observe how ephemeral and worthless human things are. Pass then through this little space of time conformably to nature, and end thy journey in content, just as an olive falls off when it is ripe, blessing nature who produced it, and thanking the tree on which it grew.
Remember how often you have postponed minding your interest, and let slip those opportunities the gods have given you. It is now high time to consider what sort of world you are part of, and from what kind of governor of it you are descended; that you have a set period assigned you to act in, and unless you improve it to brighten and compose your thoughts, it will quickly run off with you, and be lost beyond recovery.
Let it be your constant method to look into the design of people's actions, and see what they would be at, as often as it is practicable; and to make this custom the more significant, practice it first upon yourself.