While reading random blogs online (Daily Dish, if you must know), I came across an interesting story about a woman with "perfect memory":
Price can rattle off, without hesitation, what she saw and heard on almost any given date. She remembers many early childhood experiences and most of the days between the ages of 9 and 15. After that, there are virtually no gaps in her memory. "Starting on Feb. 5, 1980, I remember everything. That was a Tuesday."
She can also date events that were reported in the media, provided she heard about them at the time. When and where did the Concorde crash? When was O.J. Simpson arrested? When did the second Gulf war begin? Price doesn't even have to stop and think. She can effortlessly recite the dates, numbers and entire stories.
"People say to me: Oh, how fascinating, it must be a treat to have a perfect memory," she says. Her lips twist into a thin smile. "But it's also agonizing."
In addition to good memories, every angry word, every mistake, every disappointment, every shock and every moment of pain goes unforgotten. Time heals no wounds for Price. "I don't look back at the past with any distance. It's more like experiencing everything over and over again, and those memories trigger exactly the same emotions in me. It's like an endless, chaotic film that can completely overpower me. And there's no stop button."
She's constantly bombarded with fragments of memories, exposed to an automatic and uncontrollable process that behaves like an infinite loop in a computer. Sometimes there are external triggers, like a certain smell, song or word. But often her memories return by themselves. Beautiful, horrific, important or banal scenes rush across her wildly chaotic "internal monitor," sometimes displacing the present. "All of this is incredibly exhausting," says Price.
Based on other research I have read casually, it seems that we evolved the ability to selectively remember items because it helped with learning. Having too much information was not beneficial. As the article notes, Price's episodic memory is nearly flawless, but her semantic memory (the memory associated with learning facts and concepts) is average, which is why she did not stand out in school. Still, if she exists, there are likely people with nearly flawless semantic memory, right? The whole thing makes one wonder where the true limits of human ability lie.