My needs changed. When I was a child I had an intense need to master new skills and show them off. Video games could meet that need in a way school never could. As an adult I can completely fill those needs with work so I have no interest in those sorts of games. Now I play games to be entertained and delighted. If I want challenge I'll put that energy towards earning a bigger bonus for Q4.
Oh would you look at that all your effort went to your bosses bonus, better play harder next time...in all seriousness that's a fun way to look at work.