I've only done it once when I was in town visiting a friend. I guess explaining my situation should give context, my grades before switching to a math major were sub-par(and by that I mean terrible); I did well in a couple of courses, one with the dept. chair and he helped me get a job this summer with an incredible prof. at my department despite the fact I didn't get NSERC funding. The summer went great after a rough start and my advisor thinks I'll have a paper or two to publish this year, and I've totally fallen in love with math. I'm super interested in number theory just from the exposure you get to it from group/ring theory, discrete math and real analysis. I showed up at the nearest school with a graduate dept. while in town visiting a friend, and ended up talking to the chair of the department since he researches number theory. He was incredibly friendly, but I'm almost worried I committed a faux-pas; I have 2 years left of undergrad, and I'm not sure if it's too early to start sucking up to grad schools(and I'm aware of the fact that I'll probably need to). I'm going to be visiting my friend who goes to my dream school, Mcgill, in the winter semester. Is it kosher to visit, or should I just leave it be?