“… please Lady… Do not speak of it. I was young and foolish."
"You most certainly were."
"You are cruel, Evanna.”

Source: Translations, The Aeneid of Virgil (1866), Book II, p. 39

MM Lee Kuan Yew, after 2006 Elections http://www.washingtonpost.com/world/singapore-tries-to-imagine-a-future-without-lee-kuan-yew/2015/03/18/b12acc7c-cbe7-11e4-8730-4f473416e759_story.html
2000s

Source: The Vastalimi Gambit (2013), Chapter 11

Source: Talks for the Times (1896), "The Importance of Correct Ideals" (1892), p. 272

As quoted in "Ingmar Bergman: Summing Up A Life In Film" by Michiko Kakutani in The New York Times Magazine (26 June 1983).
Context: I was very cruel to actors and to other people. I think I was a very, very unpleasant young man. If I met the young Ingmar today, I think I would say, "You are very talented and I will see if I can help you, but I don't think I want anything else to do with you." I don't say I'm pleasant now, but I think I changed slowly in my 50's. At least I hope I've changed.

Attributed to Chesterfield by George Agar-Ellis, 1st Baron Dover, in his 1833 edition of Horace Walpole's letters to Sir Horace Mann, such statements have been attributed to many others, such as Lord Chief Justice Campbell, William Henry Maule (in the form "You silly old fool, you don't even know the alphabet of your own silly old business"), Sir William Harcourt, Lord Pembroke, Lord Westbury, and to an anonymous judge, and said to have been spoken in court to Garter King at Arms, Rouge Dragon Pursuivant, or some other high-ranking herald, who had confused a "bend" with a "bar" or had demanded fees to which he was not entitled. George Bernard Shaw uses it in Pygmalion (1912) in the form, "The silly people dont [sic] know their own silly business." Similar remarks occur in Charles Jenner's The Placid Man: Or, The Memoirs of Sir Charles Beville (1770): "Sir Harry Clayton ... was perhaps far better qualified to have written a Peerage of England than Garter King at Arms, or Rouge Dragon, or any of those parti-coloured officers of the court of honor, who, as a great man complained on a late solemnity, are but too often so silly as not to know their own silly business." "Old Lord Pembroke" (Henry Herbert, 9th Earl of Pembroke) is said by Horace Walpole (in a letter of 28 May 1774 to the Rev. William Cole) to have directed the quip, "Thou silly fellow! Thou dost not know thy own silly business," at John Anstis, Garter King at Arms. Edmund Burke also quotes such a remark in his "Speech in the Impeachment of Warren Hastings, Esq." on 7 May 1789: "'Silly man, that dost not know thy own silly trade!' was once well said: but the trade here is not silly."
Disputed

As quoted in "Did I say This? in The Observer (20 April 2008)
2008

Source: The Lorax (1971)
Context: I am the Lorax who speaks for the trees,
Which you seem to be chopping as fast as you please!
But I'm also in charge of the brown Bar-ba-loots,
Who played in the shade in their Bar-ba-loot suits,
And happily lived, eating Truffula fruits.
Now, thanks to your hacking my trees to the ground,
There's not enough Truffula fruit to go 'round!
And my poor Bar-ba-loots are all getting the crummies
Because they have gas, and no food, in their tummies!

As quoted in George Leggett, The Cheka: Lenin’s Political Police (1981), page 57.
Attributions