Do physics undergraduate students understand their strengths and weaknesses?

Physics and non-physics majors self evaluation and confidence responses to exams in undergraduate physics are compared to the student's actual success in the exams. The confidence was sampled in a variety of freshman and sophomore physics courses before and after the exams were taken. Undergraduate populations fall into two sub-groups: Students who do have a general awareness whether they have comprehended a topic and students who have not. The divide is all the more surprising as there are students who excel and have no or little confidence that they do excel and as there are students who fail completely and do not see it coming. There is little change in student's understanding of their comprehension during a given term or between terms.