A.

“People who deny the existence of dragons are often eaten by dragons. From within.”
― Ursula K. Le Guin, The Wave in the Mind: Talks and Essays on the Writer, the Reader and the Imagination

“Presume not that I am the thing I was;
For God doth know, so shall the world perceive,
That I have turn'd away my former self;
So will I those that kept me company.”
― William Shakespeare, Henry IV, Part Two

“It is sometimes an appropriate response to reality to go insane.”
― Philip K. Dick, VALIS

“Finally, from so little sleeping and so much reading, his brain dried up and he went completely out of his mind.”
― Miguel de Cervantes Saavedra, Don Quixote