Although I hate to make the college/work analogy, it seems to hold. A student's job is going to school. The rest of the things college students have to deal with are just distractions and weak excuses. 
As professors, we'd love to be able to excuse our own bad days with "We have a lot to deal with." We research, teach, grade, go to meetings, deal with bosses and subordinates, manage lives that often include children, spouses, pets and money challenges. If we came to our own classes with the same kind of lame excuses students use, they'd roll their eyes and think we were incompetent.
Recently this site featured a post from a student who listed a large number of responsibilities that she was dealing with (including bad cafeteria food, not having enough duct tape, and calls from friends back home). If she really takes her education seriously, she wouldn't let anything but the most tragic of the adult challenges get in the way. Adults get their stuff done and behave like adults, whether or not their surroundings are as easy as living with mom and dad in the suburbs.
At least, please don't give me an excuse for not being prepared for class. We all have plenty to deal with on our own and all of your professors have been young adults and managed to survive somehow. All we expect is that you give school your best shot and don't whine to us or expect special treatment when your social-butterfly roomie makes it hard for you to concentrate....
