Hmm, maybe it's just a wily plot on their part to get a glimpse of your rippling biceps.. ;)
Or maybe they want something to sleep in.. I mean how much cooler can you get than a nightgown with 'Nortel Networks' on it!
Speaking of school wear, you can certainly tell there is a gender imbalance, when the "Faculty of Math" t-shirts in the university store only come in 'Huge Guy' and 'Ogre' sizes... meanwhile, the Arts faculty has tons of girl-sized stuff. >_< (it's a continuing beef with me, can't you tell?) You think it's a shadowy conspiracy to get the math/cs girls to walk around shirtless?