In the chapter about Mr. Thompson, the man with Korsakov's, Sacks says: "a young writer named David Gilman sent me a manuscript of his book Croppy Boy, the story of an amnesiac like Mr. Thompson, who enjoys the wild and unbridled license of creating identities, new selves, as he whims, and as he must--an astonishing imagination of amnesiac genius, told with positively Joycean richness and gusto."

Was this book ever published? I can't find anything about it through Google easily, except that mention itself.