"To repeat to yourself a thousand times a day: “Nothing on earth has any worth,” to keep finding yourself at the same point, to circle stupidly as a top, eternally... For there is no progression in the notion of universal vanity, nor conclusion; and as far as we venture in such ruminations, our knowledge makes no gain: it is in its present state as rich and as void as at its point of departure. It is a surcease within the incurable, a leprosy of the mind, a revelation by stupor. A simple-minded person, an idiot who has experienced an illumination and grown used to it with no means of leaving it behind, of recovering his vague and comfortable condition-—such is the state of the man who finds himself committed in spite of himself to the perception of universal futility. Abandoned by his nights, virtually a victim of a lucidity which smothers him, what is he to do with this day which never manages to end? When will the light stop shedding its beams, deadly to the memory of a night world anterior to all that was? How far away chaos is, restful and calm, the chaos dating from before the terrible Creation, or sweeter still, the chaos of mental nothingness!"
January 1, 1970
https://en.wikiquote.org/wiki/Philosophical_pessimism