Are mistakes inevitable? I made two fairly noticeable ones at tonights gig. The band leader gave me the "look"... however at set-break I talked to a few friends in the audience (yes they would tell me the truth) and they said my playing sounded great, and they didnt notice any mistakes. They were non-musicians though. I can play the material easily enough, so its not a matter of technique. I just simply lose my concentration and my mind drifts off. Is this common for you guys? Is it inevitable to make mistakes when playing for 3+ hours, or is it just because I'm still a hack?