"The heaviest weight. – What if one day or one night a demon slinked after you into your loneliest loneliness and said to you: “This life, as you live it now and as you have lived it, you will have to live once more and countless times more. And there will be nothing new about it, but every pain and every pleasure, and every thought and sigh, and everything unspeakably small and great in your life must come back to you, and all in the same series and sequence–and likewise this spider and this moonlight between the trees, and likewise this moment and I myself. The eternal hourglass of existence is turned over again and again– and you with it, you mote of dust!”
Wouldn’t you throw yourself down and gnash your teeth and damn the demon who spoke this way? Or have you ever experienced a prodigious moment in which you would answer him: “You are a god and I have never heard anything more godlike!” If that thought took control of you, it would change you as you are, and maybe shatter you. The question in each and every thing, “Do you will this once more and countless times more?” would lie as the heaviest weight upon your acts! Or how benevolent would you have to become toward yourself and toward life in order to long for nothing more ardently than this ultimate eternal sanction and seal?"

The Gay Science by Friedrich Nietzsche