What happened: After you checked in, the gate agent announced a two-hour delay. You went off for a snack, and when you returned an hour later, the flight had already left.

What the airline should do for you: Passengers should check in with gate agents for frequent updates. It is not considered the airline’s fault if you miss a flight under these circumstances, but some will put you on the next flight if a seat is available.

Next time: Stay put until a new boarding time is announced and posted and then check back frequently.