Well, by "accident" I mean the story he always tells about how some producer or whatever happened to be the first customer that walked into a music store he got a job at and offered him a job testing games or something similar to that and he then persuaded the company to give him a shot at music. Sure, you can make the point that his decision to move to California and apply at the store played a significant part in all that, but he ultimately didn't choose who walked through the door. Yeah, he very well could have made it as a musician regardless (since he's Steven Tyler's cousin), so it stands to reason that fate certainly played a part in him becoming a famous video game composer. Hence my point of these things not being 100% in your control.
I'm not trying to be such a bitter sounding jackass or a naysayer, I'm just saying people tend to be way too optimistic about music careers.