Once I was asleep and my pager went off. Wife had to wake me up so I'd switch it off.
My worst was falling asleep (and snoring I think) during prayer time at the end of a Bible Study; while they were praying for me (yes Nikos I'd two glasses of wine that night). I woke up, looked around and for a second all was normal; then everyone else started laughing. It is still brought up from time to time.