Rosie Paley was 16 when she contracted encephalitis and suffered a huge fit – leaving her unable to remember her past.
When she came round, the frightened schoolgirl could not recognise her mum Helen or younger brothers, Rhys, four, and two-year-old Ollie.
Now, two years later, the teenager is using a photo board to try and help recollect key moments in her life.
Rosie, from Brierley Hill, Birmingham, said: “I can’t remember anything from before I was ill.
“I’ve lost all my childhood friends as I can’t recognise them.
“When I first came round, mum brought my brothers to see me. I had no idea who they were and I panicked.”
Experts say that around 4,000 new cases of Rosie’s illness are identified in the UK every year.
It is caused by the herpes simplex virus, responsible for cold sores and chicken pox.
In August 2011, Rosie was rushed to hospital after she had the fit and fell down the stairs.
“When she came round, her long-term memory had been erased.
“She even forgot her favourite food, pop band and the fact that she knew how to ride a horse.
Mum Helen, 36, said: “When Rosie woke up and said, ‘Who are you?’ I was heartbroken and terrified.
“Luckily, she slowly began to recognise me.
“She asked for her favourite childhood teddy, Baa Lamb, which is still the only thing she remembers.
“I surrounded her with family and things that might help her memory.
“We even went to a Steps concert, as they were her favourite band, but she couldn’t recognise any of the songs.”
Speaking about her photoboard, Rosie – who is training to be a hairdresser – said: “When I look at the photographs I see how happy I was, but it just draws a blank in my head.
“I wish I had the memories to go with the pictures.
“However, life is now about making new memories.”