My craziest missed flight experience: ORD to IAD, on a Sunday. I was visiting family a few years ago, and didn't realize how long it would take to get to the airport. (Those driving me, who did know, never spoke up. Ah, family...) I got to the checkout counter only to be told it was past the cutoff time, but I could try for standby.

Since going back to my folks was not an option - no one to drive me back to ORD the next day - I tried for standby but all the flights that day were seriously overbooked. As I trudged from gate to gate with no luck, I kept running into the same group of people, also trying to get home. After about 8 hours, 5 of us (who had never met before) pooled together, rented a car, and drove to D.C. Our bags flew, and we had to go to the airport to pick them up.