The scene: A recording studio. The musician has been working on the same song for over two hours. The part is an 8-bar phrase or roughly 15 seconds of recording.
Engineer [calmly]: “Do you think we should continue?”
Musician [testy]: “Why not?”
Engineer [diplomatically]: “Well, the reason I ask is that we have made about 70 passes on this 8-bar phrase over the past two hours. Maybe we should take a break and try it again another time.”
Musician [quite angry]: “Are you telling me that I don’t know how to play this part?”
Engineer [wisely]: “No. I’m telling you that I don’t know how to record this part.”