Many years ago [more than 30, because our 30 y-o wasn't born ye!] we were sitting at the wrong gate - we were seated at Gate 13 and were SUPPOSED to be at Gate 16! When we realized our mistake, we hurried to the correct one but the flight attendant wouldn't let us board - she said that the door was already closed, so we watched through the window as our plane finally pulled away. She did give us a $150 voucher for breakfast and added our names to the 11AM flight [our original flight was scheduled for 9:30 AM and was a connecting flight in Charlotte, NC]. Needless to say, we missed our connecting flight, arriving at MCO 2-1/2 hours later. To this day, I only book non-stop direct flights!