Air travel does not typically bring out the best in people. The stress of tight connections, long lines, cramped cabins and general transit fatigue can push even the calmest travelers to their limits. But that doesn’t mean you have to add to the unpleasantness. Indeed, there are many things passengers do that make the flight experience worse for their fellow travelers ― from the airport to boarding and even deplaning. On the latter front, the lack of courtesy has gotten particularly dire. “It’s