From Arthur Schopenhauer in The Wisdom of Life:
…what a man is contributes much more to his happiness than what he has, or how he is regarded by others. What a man is, and so what he has in his own person, is always the chief thing to consider; for his individuality accompanies him always and everywhere, and gives its color to all his experiences. In every kind of enjoyment, for instance, the pleasure depends principally upon the man himself. Every one admits this in regard to physical, and how much truer it is of intellectual, pleasure. When we use that English expression, “to enjoy one’s self,” we are employing a very striking and appropriate phrase; for observe — one says, not “he enjoys Paris,” but “he enjoys himself in Paris.” To a man possessed of an ill-conditioned individuality, all pleasure is like delicate wine in a mouth made bitter with gall. Therefore, in the blessings as well as in the ills of life, less depends upon what befalls us than upon the way in which it is met, that is, upon the kind and degree of our general susceptibility. What a man is and has in himself — in a word personality, with all it entails, is the only immediate and direct factor in his happiness and welfare. All else is mediate and indirect, and its influence can be neutralized and frustrated; but the influence of personality never.