I did something similar. I was flying to meet my husband after his mother died. I was grieving. I was tired because I hadn't had any sleep the night before and I'd had two bloody mary's. I changed planes and fell asleep before takeoff. I *THOUGHT* we had taken off or at least I dreamt it, so I went to the lav needing to go. They made an announcement and I was SO embarrassed for my major gaffe. At least I was in first and had to only face a few angry faces. I was mortified.