Your first instinct in a crisis is to panic. Your second instinct is to remember you shouldn't panic. Heroes can't panic when they've got a world to save or a fortress to escape from or a Big Bad to fight, and teens can't panic when their simple plan goes awry. So in the most panic-worthy of situations, someone in the group will say this phrase. Someone being Genre Savvy may point out, "Actually, yeah, it is!" Or, between 5 seconds and 5 minutes later, some tiny change worsens the situation so severely, they do a Verbal Backspace and say, "Now panic!"