BYU students would be surprised to realize just how annoying they really are.
The well-mannered person attempts to make those around him or her as comfortable as possible in every situation. This extends to any occasion where two or more people occupy the same breathable air and/or are forced to see, hear, smell, feel, or (in rare occasions) taste one another.
Even if I never acknowledge a fellow classmate, I still enter into a social relationship with him or her and am responsible to uphold my end of the social bargain, which we have come to term “etiquette” — pulling our legs in underneath our bodies when we sit in a heavily trafficked hallway, attempting a second time to park between the lines, using words such as “excuse me,” “thank you” and, above all, “please.”