“ We others, however, can be made perfectly miserable by trifling misfortunes; perfectly happy, not by the world. Whatever one may say, the happiest moment of the happy man is the moment of his falling asleep, and the unhappiest moment of the unhappy that of his awaking. ”
 Arthur Schopenhauer, The World as Will and Representation (1819). copy citation

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“But we do not need to go so far: [pg 389] at the age of five years to enter a cotton-spinning or other factory, and from that time forth to sit there daily, first ten, then twelve, and ultimately fourteen hours, performing the same mechanical labour, is to purchase dearly the satisfaction of drawing breath. But this is the fate of millions, and that of millions more is analogous to it.
We others, however, can be made perfectly miserable by trifling misfortunes; perfectly happy, not by the world. Whatever one may say, the happiest moment of the happy man is the moment of his falling asleep, and the unhappiest moment of the unhappy that of his awaking. An indirect but certain proof of the fact that men feel themselves unhappy, and consequently are so, is also abundantly afforded by the fearful envy which dwells in us all, and which in all relations of life, on the occasion of any superiority, of whatever kind it may be, is excited, and cannot contain its poison.” source