Playing Bass

This is a recurring dream. I had it again a couple of days ago. I get invited to sit in with a friend's band at a really big show after their bass player is found to be unavailable. The problem is, I don't play bass. I jump around on stage and fake it but it's increasingly clear that I'm not pulling it off. I hit strings and pull strings but the guys in the band are trying to decide just how bad I am. Am I warming up or is this as good as it gets? The dream really stresses me out, the being in front of an audience unprepared part and I wake up before it goes anywher.