Here are 2 documentaries about everyday people with incredible mental abilities!

Daniel Tammet (born 31 January 1979 as Daniel Paul Corney) is an English writer, essayist and autistic savant. Tammet has been studied repeatedly by researchers in Britain and the United States, and has been the subject of several peer-reviewed scientific papers.

Mental calculators are people with a prodigious ability in some area of mental calculation, such as multiplying large numbers or factoring large numbers. Some rare mental calculators are autistic savants, with a narrow area of great skill and poor mental development in other directions, but many are people of normal mental development who have simply developed advanced calculating ability. A good many are also experienced scientists, linguists, writers, and so on.

The Real Rain Man - Documentary:
Kim Peek is arguably the world's most famous savant and the inspiration behind the Oscar-winning film, Rain Man. Described as "a living Google", Kim is a confounding mix of disability and brilliance that has baffled neurosurgeons. Most savants have only one dominating interest, but Kim seems to soak up everything: from sport to politics and even the minutiae of the British monarchy.

Peek was born in Salt Lake City, Utah with macrocephaly, damage to the cerebellum, and 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 unusual connections due to the absence of a corpus callosum, which resulted in an increased memory capacity. According to Peek's father, Fran Peek, Kim 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 could speed through a book in about an hour and remember 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. He could read two pages at once, one with each eye. According to an article in The Times newspaper, he could accurately recall the contents of at least 12,000 books. Peek lived in Murray, Utah and spent a considerable amount of his time reading at the Salt Lake City Library and demonstrating his capabilities at schools, with great help from his father.

Peek did not walk until the age of four and then in a sidelong manner. He could not button up his shirt and had difficulty with other ordinary motor skills, presumably due to his damaged cerebellum, which normally coordinates motor activities. In psychological testing, Peek scored below average (87) on general IQ tests.

In 1984, screenwriter Barry Morrow met Peek in Arlington, Texas; the result of the meeting was the 1988 movie Rain Man. The character of Raymond Babbitt, although inspired by Peek, was portrayed as having autism. Dustin Hoffman, who played Babbitt, met Peek and other savants to get an understanding of their nature and to play the role accurately and methodically. The movie caused a number of requests for appearances, which increased Peek's self-confidence.

Barry Morrow gave Kim his Oscar statuette to carry with him and show at these appearances; it has since been referred to as the "Most Loved Oscar Statue" as it has been held by more people than any other. Kim also enjoyed approaching strangers and showing them his talent for calendar calculations by telling them on which day of the week they were born and what news items were on the front page of major newspapers. Peek also appeared on television. He travelled with his father, who took care of him and performed many motor tasks that Peek found difficult.

In 2004, scientists at the Center for Bioinformatics Space Life Sciences at the NASA Ames Research Center examined Peek with a series of tests including computed tomography and magnetic resonance imaging. The intent was to create a three-dimensional view of his brain structure and to compare the images to MRI scans done in 1988. These were the first tentative approaches in using non-invasive technology to further investigate Kim's savant abilities.

A 2008 study concluded that Peek probably had FG syndrome, a rare genetic syndrome linked to the X chromosome which causes physical anomalies such as hypotonia (low muscle tone) and macrocephaly (abnormally large head).

Kim Peek died of a heart attack on December 19, 2009 at age 58.