It was my last day at work over this past summer (I was doing research at the University of Michigan) and I was wearing sweatpants, a sweatshirt, and an ugly winter hat. I was supposed to have a final meeting with the professor I had been working for as well as the graduate students in his group. When the professor saw me, he told me my attire was unacceptable and made it clear that he thought it was very unprofessional. I tried to explain it away by saying they were my travel clothes (to fly back from Michigan to my home in Massachusetts).