From Wikipedia

The Real Rain Man Dies

Kim Peek, the inspiration for the character of Raymond Babbitt, played by Dustin Hoffman,  in the movie Rain Man, died today of a heart attack. He was born November 11, 1951 and was an American prodigious savant known as a megasavant.  He had a photographic or eidetic memory, but also social developmental disabilities, possibly resulting from congenital brain abnormalities. He was not autistic and likely had FG syndrome.

Kim Peek was born with macrocephaly, damage to the cerebellum, and, perhaps most important, agenesis of the corpus callosum, a condition in which the bundle of nerves that connects the two hemispheres of the brain is missing; in Peek's case, secondary connectors such as the anterior commissure were also missing. There is speculation that his neurons made other connections in the absence of a corpus callosum, which results in an increased memory capacity.

According to Peek's father, Fran, Peek was able to memorize things from the age of 16-20 months. He read books, memorized them, and then placed them upside down on the shelf to show that he had finished reading them, a practice he maintained. He read a book in about an hour, and remembered almost everything he had read, memorizing vast amounts of information in subjects ranging from history and literature, geography, and numbers to sports, music, and dates. His reading technique consisted of reading the left page with his left eye and the right page with his right eye and in this way he could read two pages at time with a rate of about 8-10 seconds per page. He could recall the content of some 12,000 books from memory.

Peek resided in Salt Lake City, Utah and was a member of The Church of Jesus Christ of Latter-day Saints.

Unlike many savants, Peek had shown increasing social skills, perhaps due to the attention that had come with being perceived as the "real Rain Man". His father says that his sense of humor had been emerging since 2004 or so. Also, he had developed well beyond the stage of being a mere repository of vast amounts of information; his skills at associating information he remembers were at least one of the signs of creativity. He displayed difficulty with abstractions such as interpreting the meanings of proverbs or metaphorical terms of speech.

Although never a musical prodigy, Peek's musical abilities as an adult were receiving more notice when he started to study the piano. He apparently remembered music he heard decades ago and could play it on the piano, to the extent permitted by his limited physical dexterity. He was able to give running spoken commentary on the music as he played, for example, comparing a piece of music to other music he had heard. In listening to recordings he could distinguish which instruments play which part and was adept at guessing the composers of new music by comparing the music to the many thousands of music samples in his memory.