mc5 - ... so help me God.

I was a pool hustler until I was blackballed.

I was a fence-builder until I was shown the gate.

I used to be a mountain climber, but I quit in a fit of peak.

I used to be a human cannonball, but they wouldn't fire me, so I lost my job. :)

I used to be a zooological keeper, but there were claws in my contract that led to my release.