Too funny Dave.

You wouldn't be the only muso to forget parts of your own songs.

I remember when Kiss reformed with their original lineup a few years ago they had Tommy Thayer brought in to teach Ace Frehley all the original parts & solos and when they got to Oz they booted him off the tour and replaced him with the guy hired to teach him how to play his own parts. How sad and embarrassing but I suppose that is what lots of booze and drugs can end up doing to someone.