Well, that's Boston -- and it's not, as another poster suggested, that people are especially antisocial here, it's a matter of too many people/vehicles in not enough space. Put that population density in Dallas or Anaheim or Podunk and you'll get the same behavior, once they wise up enough to figure out that it's the best way to get from point A to point B. So, yes, riding in Boston means riding in very crowded conditions, and "taking the lane" means mastering the head-turn-and-check, moving with less space around you than you might ideally like, being very clear and unambiguous about your intentions, and doing whatever you're going to do quickly (because there are windows of opportunity and people do "let you in", they just don't come to a halt and smile and wave you on to do it). The upside, as in many densely populated areas, is that the speeds aren't as fast as they are out in the 'burbs, which makes it easier to blend with the traffic. Also, sight lines are really good on Comm Ave, and in most places it's very easy to spot any entering traffic.

BTW, if you are finding that the students are really nutty-making, you might try adjusting your commute time. I'm generally riding along that stretch sometime between 7 and 8 am, and the kids are generally not up and at 'em at that hour unless they really have to be.