Taking Off My Sweatshirt

For some reason I've never figured taking of my sweatshirt creates the kind of response I would expect if some teacher in American took off there shirt entirely or maybe there pants. I used to think it was just a function of the fact that Chinese people seem to think it's better to be roasting hot then even slightly cold, so that on warm days I'll still see people in long underwear and jackets. But even when some people in the class are wearing t-shirts if I take off my sweatshirt everyone starts murmuring. Maybe it's some part of Chinese modesty I don't understand where even if it would be appropriate to wear a t-shirt somehow taking off my sweatshirt is an intimate act. I never really have understood all the rules for modesty in China. Women who would never be caught dead in skin tight clothing will walk around a train with hundreds of strangers in nothing but there long underwear. On that boat trip I took with Sean and Sarah there were men walking around in basically there boxers even in the lunch room. Well maybe there are just some things about China I'll never get.