Scientists are amazed by a housewife dubbed the "human calendar" because of her remarkable ability to remember absolutely every detail of her life from the past 25 years.
The woman has such a powerful memory that given any date since 1980 she can instantly remember whom she met, what she did – and even the weather and what she ate for dinner.
Scientists have never encountered anyone with a similar ability before, and have had to devise a name for her condition: "hyperthymesia".
Yesterday, the 40-year-old American woman, who asked to be identified only as AJ, told Britain’s The Mail on Sunday: "Let’s say someone asks me about March 1, 1981. All they have to say is the date and then – boom – the day appears in my head just like that.
"No tricks, no counting backward or forward. It is as if I put a video of Sunday, March 1, 1981 in the VCR and then watched the day."
Her ability to recall events accurately and in such detail, without the use of any memory tricks, stunned Californian researchers.
Asked for the dates of Easter from 1980 to 2003, AJ produced a faultless list, and even wrote down what she did each Easter. Because she had kept a diary scientists were able to check her recollections.
Given the date October 3, 1987, AJ said: "That was a Saturday. Hung out at the apartment all weekend, wearing a sling – hurt my elbow." She was also able to tell researchers immediately the dates of world events, including a minor earthquake and the final episode of television show Dallas.
AJ first became aware of her skills in 1978, when she was 12.
It was not until 2000 that AJ, fed up with the "running movie" in her head, decided to find out why.
She wrote to James McGaugh, a Californian expert on memory, describing her case: "It is non-stop, uncontrollable and totally exhausting," she wrote. "I run my entire life through my head every day and it drives me crazy."
Although initially sceptical, Dr McGaugh recognised AJ’s near-perfect powers of recall were unique. "She never looks at the sky or puts her hands to her forehead, as people often do when remembering something. It is very relaxed," he said.
Dr McGaugh’s research has shown humans have vivid memories of emotional or traumatic events because the body releases stress hormones that enhance memory. This explains why people can recall where they were on occasions such as the 9/11 attacks. But it does not explain AJ’s case.
Scientists believe she may have a disorder of the same part of the brain affected by autism, Attention deficit hyperactivity disorder and schizophrenia. They hope brain scans will provide answers.
For AJ, her talent is both a blessing and a curse. "I never forget anything, good or bad, so it is hard to move on – but the flip side is I am comforted by my memory," she said.