Sounds like this chap could well be an international spy ala Jason Bourne (whose trilogy also began with complete memory loss of who he was), being trained in multiple languages and identities, and being involved in dangerous top-secret technologies, abductions "I had on my wrists very big, very bloody traces of plastic strips that they use to tie up cables" and secretly developed mind-altering drugs often employed by spy agencies, that could explain his memory loss, as well as the "interesting" but undisclosed information from the governments of Czech Republic, Norway, and others.
[Europe] - Mystery man 'Jason Bourne' loses memory of who he is
https://sg.news.yahoo.com/robbed-sexually-assaulted-says-norway-mystery-man-183102285.html
[Europe] - Mystery man 'Jason Bourne' loses memory of who he is
https://sg.news.yahoo.com/robbed-sexually-assaulted-says-norway-mystery-man-183102285.html
