“Reality, as usual, beats fiction out of sight.”

Source: Life of Pi

Attributed to an interview on Larry King Live; also quoted in Quotable Quotes (1997) edited by Deborah Deford
Attributed variant: The difference between fiction and reality is that fiction has to make sense.
Clancy here expresses an idea evoked in similar statements made by others, all derived from the orignial made by Lord Byron:
Lord Byron: Truth is always strange; stranger than fiction.
Mark Twain: Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities, truth isn't.
G. K. Chesterton: Truth must necessarily be stranger than fiction, for fiction is the creation of the human mind and therefore congenial to it.
Leo Rosten: Truth is stranger than fiction; fiction has to make sense. (attributed)
1990s

Comments to James H. Wilson (22 October 1864), as quoted in Under the Old Flag: Recollections of Military Operations in the War for the Union, the Spanish War, the Boxer Rebellion, etc Vol. 2 (1912) by James Harrison Wilson, p. 17.
1860s, 1864
Context: I am a damned sight smarter man than Grant. I know more about military history, strategy, and grand tactics than he does. I know more about supply, administration, and everything else than he does. I'll tell you where he beats me though and where he beats the world. He doesn't give a damn about what the enemy does out of his sight, but it scares me like hell. … I am more nervous than he is. I am more likely to change my orders or to countermarch my command than he is. He uses such information as he has according to his best judgment; he issues his orders and does his level best to carry them out without much reference to what is going on about him and, so far, experience seems to have fully justified him.

Source: The Stanislaski Brothers: Mikhail and Alex

Letters to World Citizens (2004)

"Inner Landscape : Interview with J.G. Ballard" by Robert Lightfoot and David Pendleton, in Friends No. 17 (30 October 1970) http://www.jgballard.ca/media/1970_oct_friends_magazine.html; also quoted in The Columbia Dictionary of Quotations (1993) by Robert Andrews
Context: A hundred years ago one has the impression that people had made a clear distinction between the outer world of work and of agriculture, commerce and social relationships — which was real — and the inner world of their own minds, day-dreams and hopes. Fiction on the one hand; reality on the other. This reality which surrounded individuals, the writer's role of inventing a fiction that encapsulated various experiences going on in the real world and dramatising them in fictional form, worked. Now the whole situation has been reversed. The exterior landscapes of the seventies are almost entirely fictional ones created by advertising, mass merchandising… politics conducted as advertising. It is very difficult for the writer.
Given that external reality is a fiction, the writer's role is almost superfluous. He does not need to invent the fiction because it is already there.

Shadow and Act (New York: Random House, 1964), Introduction, p. xix; in The Collected Essays, ed. John F. Callahan (New York: Modern Library, 1995), p. 56.