A hospital has launched an appeal to identify a man who cannot remember his own name.
The man, who has been named Robert by doctors, was found in a park in Peterborough suffering from a severe case of amnesia.
He cannot recall any details of his life including his name, age or where he is from.
Nearly two months since he was found there has been no improvement in his condition.
Robert said: "The last few weeks have been truly horrible. I go through so many different emotions. At times I am angry, frustrated, depressed, lost and confused. I just need to find out my name and I hope someone out there will recognise me and help."
The man was found in a park near the city's bus station at 6am on May 18. He was not carrying a wallet, mobile phone or any documents.
Robert told police he had no memory of who he was or how he came to be in the park.
He is believed to be in his early 20s about 5ft 9ins tall, and weighs 13st. He has dark hair and blue eyes. Although he speaks English, his accent is thought to be eastern European and he understands some Lithuanian and Russian.
He was taken to Peterborough City Hospital then transferred to the nearby Cavell Centre which specialises in mental health care, where experts are trying to help him regain his memory.
Dr Manaan Kar Ray, clinical director of acute care at the Cambridge and Peterborough NHS Foundation Trust, said Robert was suffering from a very severe case of amnesia.
"Amnesia can last for anything from a few hours to a number of weeks," he added.
"Clearly this is very upsetting for him as he cannot recall any details of his life including his own name, age, where he is from, or what he does for a job.
"We have made strenuous efforts to help him with his memory - including taking him back to where he was found - but nothing has been successful so far.
"Our staff have spent a lot of time with him, helping him to recall day-to-day activities, and he can use a computer and play football and basketball, but we are still no closer to finding out who he is.
"Understandably, he is now getting very frustrated and I hope this appeal will mean someone will recognise him and come forward."
Anyone with information should contact the trust on 01733 776014 between 8am and 8pm. Lines are open every day.
Cambridgeshire Police say the man is not known to police and does not match any missing persons reports.