Santayana said: "A fanatic redoubles his effort when he has forgotten his aim." So, you could keep trying, or, you could cheat. Thomas Cathcart and Daniel Klein, on re-framing the Iraq war: "You shoot a bunch of holes in the barn door and then draw a target around them. 'See that, guys? Got a bull's eye every time!'" The idea may get stuck. Clive James: "There is no reasoning someone out of a position he has not reasoned himself into."
But, if possible, the privilege of coming up with a new theory. Sidney Morgenbesser: "So if not p, what? q maybe?"
Sometimes the truth is complicated, and it is our minds that must adjust to it. In the collected work Praeputii Incisio:
"The hardest to convince are those who insist on having a double-track fact driven through their single-track understanding, without it ever occurring to them that the latter, and not the fact, is the faulty article."
The most important truths may be the simple ones. Rebecca West: "The trouble about man is twofold: He cannot learn truths which are too complicated; he forgets truths which are too simple."
Santayana. Quoted in Clive James. Cultural Amnesia: Necessary Memories from History and the Arts. (2007) New York: Norton, 2008. p. 238.
Thomas Cathcart and Daniel Klein. Aristotle and an Aardvark Go to Washington: Understanding Political Doublespeak Through Philosophy and Jokes. New York: Abrams Image, 2008. p. 21.
Clive James. Cultural Amnesia: Necessary Memories from History and the Arts. (2007) New York: Norton, 2008. p. 61. A similar quotation ("It is useless to attempt to reason a man out of a thing he was never reasoned into.") has elsewhere been attributed to Jonathan Swift (quoted in the Sioux City, Iowa Journal. Re-quoted in The Week, Oct. 18, 2013, p. 17), Benjamin Franklin, Oscar Wilde, but the original source is difficult to find and it is not in Bartlett's Quotations.
Sidney Morgenbesser. Quoted in John Allen Paulos. Irreligion: A Mathematician Explains Why the Arguments for God Just Don’t Add Up. New York: Hill and Wang, 2008. p. 26.
Anonymous [Dr. Peter Remondino]. Praeputii Incisio: A History of Male and Female Circumcision with Chapters on Hermaphrodism, Infibulation, Eunuchism, Priapism and divers other Curious and Phallic Customs. Privately printed. New York: The Panurge Press, 1931. p. 16.
Rebecca West, quoted in the Wall Street Journal, quoted in The Week, Sept. 27, 2013. p. 17.