Unfortunately, YES. It was about 16 or 17 years ago. I was in a smaller airport and was asleep about 30-40 feet from the gate. I was in college and had pulled an allnighter to get work done before flying east for spring break.

When I woke up, the gate was empty. I went downstairs and talked to the person at the NW desk. I said I was on the flight, and the agent said, "No you weren't". Apparently, the FA took a headcount and thought everyone was on board. They flew with my bag on board and everything. It was the last flight of the day too.

They didn't make me buy a new ticket because they knew they made a mistake (as did I by oversleeping). Did they think I was sleeping right by the gate for my own health? If they had done the headcount right, they likely wouldn't have left without me.