A display showing the 'fasten your seatbelt' sign and the 'no smoking' sign illuminated on board an aircraft.You trudge down the aisle to your seat. You double- and triple-check that you've arrived at the right row. You heave your luggage into the overhead bin and squeeze past your fellow passenger to settle into your seat.Job done. Stress-filled boarding process complete. You zone out.Never mind that flight attendants have begun their pre-flight safety demonstration, or that a video has begun to play infor ...