The author immediately reveals that he has savant syndrome, which he says entails “an almost obsessive need for order and routine” (1). He notes that many savants “suffer profound disability” that hinders communication and interview-style study of the syndrome (6). Individuals with savant syndrome excel in certain skills and abilities, most commonly related to memory, calculation, and patternmaking. Other famous cases of people with savant syndrome have included uncommonly talented musicians, map makers, and artists. Many people with savant syndrome are also on the autistic spectrum. It is a rare condition globally, unlike autism.

As the author became a well-known public figure, people began asking him to flex his savant abilities for entertainment. The author often agreed, wishing to enhance people’s knowledge of the mind and brain.

Synesthesia describes a set of perceptual patterns that link senses that are usually considered unrelated, like visual input triggering an auditory experience. In a common form of synesthesia, certain input (like numbers or words) might appear inherently colored, textured, shaped, or otherwise defined by qualities not routinely associated with them. Tammet says that, for him, “the number 1 […] is a brilliant and bright white” and “Five is a clap of thunder or the sound of waves crashing against rocks” (2).