I find it basically impossible to empathize with him. I just wouldn't ever be in that situation. "Rising against adversity" is not the story I'd be be using here so much as just a typical strongman bravado leading to an absolute disconnect from reality.
I would wager greatly that it's not that he's grown cynical to people saying he can't do something, but that he's become delusional from people telling him a genius. People who convince themselves that they're smart do this thing where they have an idea, and conclude that because they've come up with it and they're smart that it must be a well reasoned idea.