What, if some day or night, a demon were to steal after you into your loneliest loneliness and say to you: “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 . . . must 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 over again and again — and you with it, speck of dust!” (Walter Kaufmann, translator)
Nietzsche saw the eternal recurrence of events as a cause for joy.
He must have been addicted to suffering.