Lack of parental direction from parents who hated each other, possibly unsupervised internet access leading to porn addiction as a teenager combined with constant bullying by the 'chupapis' in his school as he was an unlikeable loner even then who grew into a fat, even more unlikeable teenager.
As to why he eventually decided his only solution was to become 'a lesbian trapped in a failed man's body' and troon out on public funds we just don't know from the limited data we have. But he was obviously tested and rated as retarded so qualified for the Chris-Chan monthly tugboat, as well as whatever medical procedures he 'needed' gratis, and one of the tranny-butchers took advantage of this to get a new pool on their property by giving our boi the dickflip to turn him into 'Amanda' on the US taxpayer's dime.
The final result of this is the brony fucktard sociopath we know today as 'Colton the Mare-Fingerer' and living embodiment of the 'Chronic Backstabbing Disorder' trope, currently performing 12+ hours a day on Kiwi Farms for your entertainment.