Perhaps something(s) happened we have no knowledge off..
He came from a dark place in life and was lucky to have escaped into the light, but maybe that still took it's toll, came back to haunt him, didn't feel all that great, for can be hard to adjust to regular society after something like that.
Especially if society isn't all that understanding and nice in general for people who don't fit into the machine as a smooth gear and will most of the time be outcast, rejected and unforgiven.
So it's probably a big struggle..
Every person has his own battles to fight and flaws to overcome