It's hard to imagine how it would feel to fall asleep, aged 38, and wake up convinced you're 15 years old.
But that's exactly what happened to Naomi Jacobs from Manchester, who woke up in 2008 believing it was 1992 - all because of a rare form of amnesia which had completely wiped her memory.
The mum-of-one revealed that she was particularly "shocked" to find that she had an 11-year-old son living in her house.
Describing how she felt at the time to the BBC, she said: "Everything from fear to joy from seeing this child that I didn't have any memory of giving birth to, but knew undoubtedly that he was mine because he looked so much like me, to terror of having the responsibility of this small child."
"I was convinced that I was going to fall asleep again that night and wake up in 1992. It wasn't real to me what was happening."
After seeing a psychologist, Jacobs was diagnosed with transient global amnesia; a sudden, temporary episode of memory loss.
According to the Mayo Clinic, people experiencing an episode of this type of amnesia will not be able to recall any recent events - their memory simply vanishes.
The clinic's website reads: "You can't remember where you are or how you got there. In addition, you may not remember anything about what's happening in the here and now."
Jacobs is now set to detail her intriguing story in a memoir, Forgotten Girl, which will be released on 23 April.
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Transient global amnesia is extremely rare and affects five in 100,000 people in the UK. It's mostly brought on by stress.
At the time when her memory vanished, Jacobs revealed that she had a lot on her plate. She had recently split from the father of her child and was studying for a psychology degree while trying to keep her homeopathy business afloat.
Psychologists believe that all of these stress factors caused the 'episodic' part of her memory to shut down, resulting in a complete loss of emotional memories.
However, Jacobs' semantic memory - the practical part of your brain which remembers phone numbers and how to drive - was still fully intact.
Since the shocking condition took hold, slowly but surely Jacobs has managed to collate fragments of her life and piece it back together with the help of personal diaries and relatives.
Thankfully, after eight weeks, her memory returned to normal.