Like everyone else in a society loudly lamenting a decline in civility, I recognize there are new breaches of etiquette every minute. On any typical day, cell phones alone account for the rudeness factor going off the charts. But I believe there is one type of impolite behavior among adult humans that goes pretty much unchecked. I’ve been guilty of it myself and slinked away feeling really stupid. It just isn’t something that makes it into the etiquette books and it apparently isn’t even worth Miss Manners’ fleeting consideration.