By a peculiar weakness of human nature, people generally think too much about the opinion which others form of them; although the slightest reflection will show that this opinion, whatever it may be, is not in itself essential to happiness. Therefore it is hard to understand why everybody feels so very pleased when he sees that other people have a good opinion of him, or say anything flattering to his vanity. If you stroke a cat, it will purr; and, as inevitably, if you praise a man, a sweet expression of delight will appear on his face; and even though the praise is a palpable lie, it will be welcome, if the matter is one on which he prides himself. If only other people will applaud him, a man may console himself for downright misfortune or for the pittance he gets from the two sources of human happiness already discussed: and conversely, it is astonishing how infallibly a man will be annoyed, and in some cases deeply pained, by any wrong done to his feeling of self-importance, whatever be the nature, degree, or circumstances of the injury, or by any depreciation, slight, or disregard.
The Essays of Arthur Schopenhauer - The Wisdom of Life by Arthur Schopenhauer