Individuals with hyperthymesia can recall almost every day of their lives in near perfect detail, as well as public events that hold some personal significance to them. Those affected describe their memories as uncontrollable associations, when they encounter a date, they "see" a vivid depiction of that day in their heads. Recollection occurs without hesitation or conscious effort.It is important to draw a distinction between those with hyperthymesia and those with other forms of exceptional memory, who generally use mnemonic or similar rehearsal strategies to memorise long strings of subjective information. Memories recalled by hyperthymestic individuals tend to be personal, autobiographical accounts of both significant and mundane events in their lives. This extensive and highly unusual memory does not derive from the use of mnemonic strategies; it is encoded involuntarily and retrieved automatically. Despite being able to remember the day of the week on which a particular date fell, hyperthymestics are not calendrical calculators like some people with autism or savant syndrome. Rather, hyperthymestic recall tends to be constrained to a person’s lifetime and is believed to be an unconscious process.