<p>I teach at a university in Europe (free tuition BTW) my students have a half an hour between most courses. But many walk out in the middle of class casually for 3 to 5 min--for the bathroom, for a smoke, to use their cell phones????--it's not unusual for 3 or 4 out of 50 students to do this during a 90 min. class. I find this disruptive and rude --in situations that are not emergencies. I figure I am over 50 and in over 20 years of teaching, I have never had to rush out of a 90 min session to use the bathroom--I claim no special bladder superiority, just the ability to prioritize. I tell them to please try "to take care of their personal needs " betwen classes. (It's not just my courses, colleagues report the same)-- would the attitude be different if they had to pay for tuition on an American scale?</p>