'This life as you now live it and have lived it, you will have to live once more and innumerable times more; and there will be nothing new in it, but every pain and every joy and every thought and sigh and everything unutterably small or great in your life will have to return to you, all in the same succession and sequence—even this spider and this moonlight between the trees, and even this moment and I myself. The eternal hourglass of existence is turned upside down again and again, and you with it, speck of dust!'
This idea from Nietzsche perplexes me. There is something "dark" in this that I can't quite place, and something not particulary helpful, at least for me. The "eternal return" makes sense when reminiscing pleasant or enjoyable experiences, but not for unpleasant events. I think we must choose our actions wisely, due to our understanding of what will bring the best future outcome, but if there is some kind of mistake we have made or some terrible event that happens, then we need to work through that is a much different way than what the eternal return suggests.