Coroner confirms identity of 'unknowable' man. AN ENGLISHMAN went to extraordinary lengths to live a double life in Australia before he was found dead in a Sydney unit. Now we know who he really is. Source 2n.
The Secret Life Of The Late John Pritchard (Hover)
I think anyone who has to hide who they really are, are one of two people. The first is not a good person as they attempt to change who they are to get away from authorities so that they can continue to crimes. The other is usually someone in danger from others and needs to have a new identity to live in peace and away from bad people. This is at times people in witness protection or situations similar.