The Germanwings co-pilot thought to have deliberately crashed his Airbus in the French Alps, killing 150 people, predicted "one day everyone will know my name", his ex-girlfriend says.
In an interview with Germany's Bild newspaper, she recalled a comment Andreas Lubitz made last year.
"One day I'm going to do something that will change the whole system, and everyone will know my name and remember," he told her.
Flight 4U 9525 crashed on Tuesday.
The woman, a 26-year-old flight attendant who flew with Mr Lubitz for five months last year, was "very shocked" when she heard the news, the paper says.
If Mr Lubitz deliberately brought down the plane, "it is because he understood that because of his health problems, his big dream of a job at Lufthansa, as captain and as a long-haul pilot was practically impossible," she told Bild.
The black box voice recorder indicates that Mr Lubitz locked his captain out of the cockpit on Tuesday and crashed the plane into a mountainside in what appears to have been a suicide and mass killing.
German prosecutors say they found medical documents at Mr Lubitz's house suggesting an existing illness and evidence of medical treatment. They found torn-up sick notes, one of them for the day of the crash.
They say he seems to have concealed his illness from his employers.
His former girlfriend told Bild they separated, "because it became increasingly clear that he had a problem".
She said he was plagued by nightmares and would at times wake up screaming "we're going down".
A fellow member of the flight school where Andreas Lubitz took lessons told the BBC the co-pilot had known the area of the French Alps where the plane crashed from going there on gliding holidays.
A French newspaper, Metro News, reported (in French) that Mr Lubitz had holidayed with his parents at a flying club nearby.
A hospital in the German city of Duesseldorf has confirmed Mr Lubitz was a patient there recently but it denied media reports that he had been treated for depression.
The theory that a mental illness such as depression had affected the co-pilot was suggested by German media, quoting internal aviation authority documents.
They said he had suffered a serious depressive episode while training in 2009.
He reportedly went on to receive treatment for a year-and-a-half and was recommended regular psychological assessment.
Mr Lubitz's employers insisted that he had only been allowed to resume training after his suitability was "re-established".
French police say the search for passenger remains and debris on the mountain slopes could take another two weeks.
In the aftermath of the crash, the EU's aviation regulator, the European Aviation Safety Agency, has urged airlines to adopt new safety rules.
In future, it says, two crew members should be present in the cockpit at all times.