Think of the totality of all Being, and what a mite of it is yours; think of all Time, and the brief fleeting instant of it that is allotted to yourself; think of Destiny, and how puny a part of it you are.

Marcus Aurelius (AD 120 – 180), Meditations (5.24)

I also quite like the Gregory Hays’ translation of this:

Remember:

Matter. How tiny your share of it.

Time. How brief and fleeting your allotment of it.

Fate. How small a role you play in it.