Imagine waking up every day knowing that you could have been a billionaire but for a single foolish decision, and having no way to get around that thought. You'd have a very poor quality of life indeed, even if you were perfectly materially comfortable. The fact that he cannot keep an Apple product hints at this; being confronted with a constant reminder would be too painful.
It's a subtle and useful lie to think of yourself or pretty much anyone else as being non-materialistic or enlightened enough as to cheerfully give up billions of dollars in wealth. No doubt if this person was given a second chance with foreknowledge, he would take the deal.
It's only afterward that we cry "sour grapes" in order to reduce our mental struggles to a manageable level.
https://en.wikipedia.org/wiki/Cognitive_dissonance#.22The_Fo...