If Mick Jagger had not been a singer, what line of work would he have pursued?

I sometimes wonder about these mega-superstars. When I was a kid, just starting to acquire a taste for the Rolling Stones, my grandpa, a VP at a large corporation, thought Mick Jagger was a slimy sub-human who couldn't sing, and who seemed to be striken with a rare disorder of the nervous system. My older brother, always a rebel, thought Jagger was an awesome role model. I loved Grandpa and my brother both, so I had trouble reconciling these divergent points of view. But really, what would MJ have done with his life if the Rolling Stones had flopped and he left the world of music as a 22 year old? What other passions and serious interests did Jagger have? Might he have had a career as a banker or a building inspector?