Fun? You want fun as well?
There's always an element of fun in anything creative, but you've also got to be deadly serious about how you approach the process. If you want to create quality games, at least.
It's like being in an orchestra. You can have fun when you're performing live at the Albert Hall, but you only get to be in the orchestra through years of dedication and practice. By being serious about becoming a top musician.
In a sense, it goes beyond being fun. My nature drives me to be creative, almost to distraction. There is practically no time of the day when I'm not thinking of something creative.