Cover to The Know it All...
|Author||A. J. Jacobs|
|Publisher||Simon & Schuster|
|LC Class||AE5.E44 J33 2004|
It recounts his experience of reading the entire Encyclopædia Britannica; all 32 volumes of the 2002 edition, extending to over 33,000 pages with some 44 million words. He set out on this endeavour to become the "smartest person in the world". The book is organized alphabetically in encyclopedia format and recounts both interesting facts from the encyclopedia and the author's experiences.
The satirist P.J. O'Rourke said of it: "The Know-It-All is a terrific book. It's a lot shorter than the encyclopedia, and funnier, and you'll remember more of it. Plus, if it falls off the shelf onto your head, you'll live."
By contrast, Joe Queenan in The New York Times Book Review contended that much of which Jacobs reported as remarkable discoveries, e.g. the tale of Heloise and Abelard and the assassination of Marat by a woman, were already common knowledge among educated people. Jacobs responded that "the ridiculously hyperbolic subtitle might have been a tip-off" of the book's ironic tone. 
A.J. Jacobs was not the first to read the entire Britannica. The earliest recorded example was Fath Ali, who upon becoming the Shah of Persia in 1797, was given a gift of the 3rd edition of the Britannica. After reading all of its 18 volumes, the Shah extended his royal title to include "Most Formidable Lord and Master of the Encyclopædia Britannica". Roughly a century later, Amos Urban Shirk, an American businessman, read the entire 23-volume 1911 Encyclopædia Britannica over a period of four years. He then went on to read the entire 14th edition, spending on average three hours per night.
In fiction, a character in Sir Arthur Conan Doyle's The Red-Headed League is hired to copy out the Britannica by hand—for no other reason (at least apparently) than his red hair—although his job is terminated before he finishes the entries beginning with "A".
- Dust jacket of The Year of Living Biblically, a later book also by A.J. Jacobs
- Banquet at Guildhall in the City of London, Tuesday 15 October 1968: Celebrating the 200th Anniversary of the Encyclopædia Britannica and the 25th Anniversary of the Honorable William Benton as its Chairman and Publisher. United Kingdom: Encyclopædia Britannica International, Ltd. 1968.
- "Reader". The New Yorker. March 3, 1934. p. 17.
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- Guth, Robert A. (April 25, 2009). "Raising Bill Gates". The Wall Street Journal.
- Reading the OED: One Man, One Year, 21,730 Pages. New York City: Perigee (Penguin Group) 2008, ISBN 978-0-399-53398-3