But S.’s ability to remember was also a hindrance in everyday life. He had a hard time understanding abstract concepts or figurative language, and he was terrible at recognizing faces because he had memorized them at an exact point in time, with specific facial expressions and features. The ability to forget, scientists eventually came to realize, was just as vital as the ability to remember.

“We’re inundated with so much information every day, and much of that information is turned into memories in the brain,” said Ronald Davis, a neurobiologist at the Scripps Research Institute in Jupiter, Fla. “We simply cannot deal with all of it.”

Researchers like Dr. Davis argue that forgetting is an active mechanism that the brain employs to clear out unnecessary pieces of information so we can retain new ones. Others have gone a step further, suggesting that forgetting is required for the mental flexibility inherent in creative thinking and imagination.

A new paper, published Thursday in the journal Science, points to a group of neurons in the brain that may be responsible for helping the brain to forget. Akihiro Yamanaka, a neuroscientist at Nagoya University in Japan, and his team stumbled across the cells, known as melanin-concentrating hormone, or M.C.H., neurons, while studying sleep regulation in mice.

 
https://www.nytimes.com/2019/09/19/science/brain-memory-forgetting-mind.html