If you notice, a lot of relationships start in the early to mid fall when we all get back to school. So that gives ur relationship about a 7-8 month shelf life. If you're compatible you'll probably last beyond that, but if you aren't you just about hit your breaking point there. Not to mention that you hit the realization that during the summer there may be separation (going home, vacation, etc) and you realize that you don't want to "hold out" until the other gets back. That's my theory that only comes from my experiences and the experience of others.

Long out of college, as are my friends and several breakups of 2, 3, 5 year relationships around us, too.