A "Paws for Politeness":
If you are fourth person in line at the checkout and the cashier at the next register shouts "I'll take the NEXT person in line", it's polite to .. you know .. actually let the next person in line be the first person in line at the newly opened register.
(CLUE: That is the second person in line. It is NOT you.)
(NOTE: If the second person in line has already put their items on the conveyor belt, and there are too many items to grab and run, that person should defer to the third person in line. Still...not you.)