I've only missed one and that was 30 years ago.

Since there wasn't another flight for a week they put us on a different route on a different airline that would get us there the next day.

However this was partially their mistake--we had been told a departure time 1/2 hour later than reality. Couple this with numerous headaches getting to the airport and we got there 2 minutes after check-in had closed. We were all over the airport trying to find out where we were supposed to check in and running into lots of language problems. We finally found someone intelligent and English-speaking who was able to tell us they had just closed the doors.