QUOTE : Phelps and Hirst surveyed several hundred people about their September 11 recollections over a period of ten years, observing the subjects’ memories deteriorate even as the subjects exhibited no clue that their deeply felt stories were morphing. All the participants whom Phelps and Hirst surveyed had formed a flashbulb memory of the 9/11 attacks. It turned out that most of the forgetting, which was manifested in errors of either omission or commission, occurred in the first year after the event. The deviations ranged from simple tweaks to wholesale revisions, and even in the case of extreme changes, the subjects were unaware that they were deconstructing and reconstructing what seemed, to them, a very stable story. Researchers believe that the act of repeating a narrative somehow contaminates it, meaning that nowhere in our brains do any permanent, unmarred memories reside, no matter how much it may feel that way.