The social rules of standing and waiting in a queue do not require explanation. When queuing at the post office, supermarket, or the theatre entrance, it is common knowledge that someone trying to enter the queue at any place but the rear end will cause, to say the least, an unfriendly reaction. Leaving the queue without good reason and without discussing this with the person behind one, may very well lead to losing one’s place in the queue. There are nuances, of course, informed by other important social norms or common decency, such as allowing leniency to queuing decorum for the infirm or disabled; or to be reasonable in allowing someone back into the queue when he/she had to leave for a good reason and with the promise of return, for ex...