Happiness is but a dream and sorrow is real, would be as false as it is, in fact, true. A man who desires to make up the book of his life and determine where the balance of happiness lies, must put down in his accounts, not the pleasures which he has enjoyed, but the evils which he has escaped. That is the true method of eudaemonology; for all eudaemonology must begin by recognizing that its very name is a euphemism, and that to live happily only means to live less unhappily–to live a tolerable life. There is no doubt that life is given us, not to be enjoyed, but to be overcome–to be got over. There are numerous expressions illustrating this–such as degere vitam, vita defungi; or in Italian, si scampa cosi; or in German, man muss suchen durchzukommen; er wird schon durch die Welt kommen, and so on. In old age it is indeed a consolation to think that the work of life is over and done with. The happiest lot is not to have experienced the keenest delights or the greatest pleasures, but to have brought life to a close without any very great pain, bodily or mental. To measure the happiness of a life by its delights or pleasures, is to apply a false standard. For pleasures are and remain something negative; that they produce happiness is a delusion, cherished by envy to its own punishment. Pain is felt to be something positive, and hence its absence is the true standard of happiness. And if, over and above freedom from pain, there is also an absence of boredom, the essential conditions of earthly happiness are attained; for all else is chimerical.
The Essays of Schopenhauer