<p>confused, it’s really just a joke. Only the kids in Math 55 really don’t have much time to do anything else because, well, their problem sets take on the order of forty hours a week. Other jokes along the same line:
Harvard computer science majors create social networks; Princeton computer science majors have social lives.
Princeton sociology majors go on to become the first lady. Harvard sociology majors have yet to touch their first lady.
The Princeton Band came up with a few more, but I can’t think of them off the top of my head.</p>