After playing Rock Band for the first time I decided to give the real thing a shot.
That's what made me pick the guitar (my first instrument ever). I was playing with some other guys who almost always gave me the bass "position" eventhough I wanted to be the guitar... In retrospect, I was like anyone else who doesn't know better (i.e. thought that the guitar was the "koolest thing evar" and wanted to play it). I was deluded into wanting to be a lead guitarist, eventhough I don't like the spotlight and I like to groove to the music much more than shredding all over the place.
But being the "bassist" in Rock Band may have been a prophesy of what I would become a couple years later.