Hitchens and Rushdie shared a sense of humor, as Rushdie explains in this NYT interview. In Hitch-22, Christopher told about a game they played, [Book] Titles That Don’t Quite Make It, which is how the Hitch-22 title originated. Rushdie explains in this 2012 piece for Vanity Fair:

Hitch-22 was a title born of the silly word games we played, one of which was Titles That Don’t Quite Make It, among which were A Farewell to Weapons, For Whom the Bell Rings, To Kill a Hummingbird, The Catcher in the Wheat, Mr. Zhivago, and Toby-Dick, a.k.a. Moby-Cock. And, as the not-quite version of Joseph Heller’s comic masterpiece, Hitch-22. Christopher rescued this last title from the slush pile of our catechism of failures and redeemed it by giving it to the text which now stands as his best memorial.

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