Hyperthymesia is a real (not fictional) condition associated with how human memory works. People with hyperthymesia can remember an incredibly large number of their life experiences, often with many slightest details.
Memories – artistic interpretation. Image credit: Dan Carp via Wikipedia, CC-BY-SA-4.0
This condition is considered abnormal – even when most of us probably would want to have such a superior memory performance. Hyperthymesia, or highly superior autobiographical memory (HSAM) also exceptionally rare – until the last year, only 62 people in the world have been diagnosed with this memory issue.
There are two defining characteristics of hyperthymesia: the first, when a person spends an excessive amount of time thinking about one's past; and the second when a person displays an extraordinary ability to recall very specific events from his/her past.
The name itself is derived from the ancient Greek words: hyper- (“excessive”) and thymesis (“remembering”).
There is no limitation to what individuals with hyperthymesia can recall in detail. It may be event events, both public and personal. There is little evidence of how specifically these memories are associated with happenings of personal significance. Hyperthymestic memory recall tends to be limited to a person's life experiences.
People with hyperthymesia often describe this condition as “uncontrollable”: it is enough for them to think of a calendar date, and they can immediately “see” what happened on that particular day in their heads, without making any conscious effort.
These memories, however, do not seem to be “stored” as exact recordings. But the number of detail included when remembering a certain scene, for example, is very large: people with this form of superior autobiographical memory may remember even what was shown on a TV screen in the background, what food was on the table, or what clothes people were dressed in.
So is hyperthymesia good or bad?
It is important to remember that hyperthymesia is not a consciously-controlled ability. People with this condition cannot choose what they want to remember, and because of this reason, they cannot use this certain advantage at work or school. Their standardized memory tests usually indicate an average or even sub-average performance when remembering names, sequences of numbers, or sets of images.
Furthermore, hyperthymestic abilities can have a detrimental effect. People may be prone to “getting lost” in memories or could be unable to stop the flow of memories, and thus experience difficulties living in the present. Even a simple talk with other people about dates or events is enough to trigger a cascade of several experiences from the past.
Also, it is important to note that hyperthymesia is not the only form of exceptional memory. You won't develop hyperthymesia if you use special mind training techniques to learn to memorize large amounts of information.