What was Tom's backstory?

Yes, I asked that in an earlier post. Tom is supposed to be 25 or 26. He was working as a piano tuner at Princeton, and then as a men's room attendant in NYC. We do not know whether or not he attended university; most likely not, given his job history. But with his assets and determination to succeed, why had he achieved so little in the 7 or 8 years since he was likely out in the world?

Tom had worked at a janitor at an Ivy League school before, finishing unsolved equations in secret during his spare time. He was a mathematical genius who was unsuccessful because of previous childhood trauma that stunted his ability to emotionally trust others. He left his girlfriend after realizing he was gay, moved to New York, changed his name, and decided to practice the arts. Eventually his photographic memory and savant knowledge came in handy for impersonating people, and that's when he met Herbert Greenleaf....

~ I'm a 21st century man and I don't wanna be here.

. . . I finally bought this DVD - been avoiding it for a while bc it seemed dull. . .
But it was actually an ok movie.
Naturally, it's based on a book (a novel which I have no time to read) so maybe there is a backstory there ...

But like you, I felt something
was missing regarding Tom's backstory . . .

But I see you all have commented on his immediate backstory . . .

I imagined his backstory actually much further back, to childhood, much more psycological;

Abusive parents:
There is a scene where Tom is
shown living in a basement-like flat and the couple above his flat are arguing & fighting.

Later in the movie he talks about his shame and guilt metaphorically 'locked away in a basement' . . .

Maybe, as a child, he was physically abused by his parents and locked in the basement. Maybe there was an old piano there where he learned to play.

There can be all kinds of reasons why he was gifted & talented, and able to carry himself - maybe the family was wealthy on one side of his parents - say, his father was raised wealthy but was rejected by the family for marrying a poor girl, which contributed to their volatile relationship & ultimately Tom's abuse - maybe the father accused the mother of having an affair - denying his paternity (which of course could be the cause of Tom's debilitating self-esteem, etc etc - need to validate his existence, reward his mother etc etc)
So he grows up to be the psychopath we watched in the movie . . .

Actually, maybe they should go back and make a movie of Tom's childhood, and let Damon narrate it as an older man, and at the very end of that film, we get surprised to see where Tom ended up.

It could be yet ANOTHER Damon narrated movie . . .