“If you wash out a few details but retain the gist, it helps you to use it in novel situations,” Richards says. “It’s entirely possible that our brain engages in a bit of controlled forgetting in order to prevent us from overfitting to our experiences.”
SDAM vs. HSAM
Those with severely deficient autobiographical memory (SDAM), however, are unable to vividly recall specific events in their lives. As a result, they also have trouble imagining what might happen in the future.
Studies of people with exceptional autobiographical memories or with impaired ones seem to bear this out. People with a condition known as highly superior autobiographical memory (HSAM) remember their lives in such incredible detail that they can describe the outfit that they were wearing on any particular day. But despite their exceptional ability to recall such information, these individuals tend not to be particularly accomplished and seem to have an increased tendency for obsessiveness, “which is exactly what you’d predict from someone who can’t extract themselves from specific instances”, says Brian Levine, a cognitive neuroscientist at the Rotman Research Institute at Baycrest Health Sciences in Toronto.
Memory, first and foremost, is there to serve an adaptive purpose.
Forgetting enables us as individuals, and as a species, to move forwards.