Not wearing a hair shirt? Do you like to take baths? Have you never suffered from the plague? Clearly you aren’t a fully legitimate medieval scholar.
Update: I just read Connie Willis, The Doomsday Book, in which basically half the plot is that to be a legitimate medieval scholar, you have to travel back in time and wear hair shirts, stop bathing, and risk the plague, or otherwise live medievally. Book highly recommended, by the way.