I'm occasionally asked how medically authentic Before I Go to Sleep is. I was very careful during the writing of it to make it as true as possible to real cases of amnesia - but, I thought, that my one concession was that my character is able to retain memories for a day, which are then wiped.
This was necessary for me to tell the story from her point of view, but I didn't think it was possible. My understanding of amnesia (or anterograde amnesia, at least) is that people can find themselves unable to code short-term memory as long-term memory, and these people would lose their memories every few minutes (as in the film 'Memento'). They wouldn't retain a whole day's worth of memory, only to lose it overnight.
But, as we were sending the book out to editors, I came across a story in a national newspaper. A woman reported exactly the same symptoms as my character - symptoms I thought I'd invented - and, chillingly, she was exactly the same age. Reading her story was odd for me - I felt in some way vindicated, but by far the bigger emotion was a profound sadness. During the writing of the book I had come closer to understanding just how terrible it must be to lose our memory, to have no sense of who we are, but I had consoled myself that, unlike my character, people who really suffer with anterograde amnesia must have only a limited understanding of what has happened, and is happening, to them. Scant comfort, but some comfort nonetheless. It was chilling to discover that someone really did have to live through the fictional situation that I had created for my character.
You can read the story here.