In "Bring a Shovel and a Gun," con artist Ali Reed's life is shaped by a rare condition called hyperthymesia.
Hyperthymesia is a neurological condition that gives an individual extraordinary retention and recall of autobiographical memories. A person with hyperthymesia can remember with startling detail virtually everything that they've seen, heard and done.
Living with hyperthymesia is not the same as having a photographic memory. People with photographic memory make a conscious effort to retain information, usually for a limit period of time.
A person living with hyperthymesia can't stop their brain from remembering or recalling the past. The mention of a specific date (Sunday, May 27, 1979) or topic (love, regret, sex, etc.) can send their minds racing back to old memories. The sense of loss, joy or anger they felt long ago suddenly returns with the same intensity it had when it first occurred.
In Ali's case, hyperthymesia is the reason why he's a great con artist. His special condition gives him the able to keep his lies straight and outsmart his marks. Hyperthymesia is also at the root of his personal problems: his fear of commitment; his trust issues; his inability to bite his tongue, even when in danger.