In the opening chapter, Tammet introduces himself and explains a bit about the way his mind works. He reveals right away that he has “a rare condition known as savant syndrome” that includes “an almost obsessive need for order and routine” (1). Part of the regular ordering of his world comes from the author’s ability to ground himself in numbers. Counting calms him down, and numbers help him be consistent with portions, routines, and seemingly every element of his life. His relationship to numbers, however, extends beyond their basic functionality. The author also reveals that he has particularly complex synesthesia, what he explains as “a neurological mixing of the senses” that allows him to “see numbers as shapes, colors, textures and motions” (2). He also identifies the “relatively mild and high-functioning form of autism” (7), called Asperger’s syndrome, that he has. He says that most people with savant syndrome are on the autistic spectrum.

Tammet provides some visual examples of what his imagining of numbers and larger life with synesthesia looks like. He illustrates certain numbers with curves and others with dots, for example. This holistic relationship with numbers is also emotional; Tammet likes certain numbers for the colors, shapes, and auras they embody in his mind and dislikes others whose sensory output is, for him, anxiety-inducing.