What is truly odd is that even though the model is attractive, when you're trying to draw her (or in the case of female artists, draw him) your mind isn't focused on anything other than "I hope I get this right."
Good points. It seemed that it was not unusual for guys to sign up for introductory drawing classes thinking they could draw, because they sketched comic-book style nudes. However, when given the task of producting a realistic drawing of a specific human being standing in front of them, they were stumped!