We know the gist of it.
On his old job he was ruthless and that spilled into his private life leading to his wife filing for divorce and that was when he took a good look at what he became, so he quit and started anew being the person we see.
We can tell that marked him and never gone over it, he still backs down from personal relationships and never acts strict ... is there a reason to go over the details? well no because the details are irrelevant.
