Persons of an advanced age, whom long experience of the folly and injustice of the world, has taught to pay little regard, either to its censure or to its applause, neglect and despise obloquy, and do not even deign to honour its futile authors with any serious resentment.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“We often esteem a young man the more, when he resents, though with some degree of violence, any unjust reproach that may have been thrown upon his character or his honour. The affliction of an innocent young lady, on account of the groundless surmises which may have been circulated concerning her conduct, appears often perfectly amiable. Persons of an advanced age, whom long experience of the folly and injustice of the world, has taught to pay little regard, either to its censure or to its applause, neglect and despise obloquy, and do not even deign to honour its futile authors with any serious resentment. This indifference, which is founded altogether on a firm confidence in their own well-tried and well-established characters, would be disagreeable in young people, who neither can nor ought to have any such confidence.” source