I managed to lock myself in a room full of locked doors.
I was attending a training seminar at work. After the lunch break I had to use the facilities, which were down a flight of stairs and a hall full of doors. After relieving myself, I attempted to make the return trip to the classroom. I opened the wrong door, couldn't find the stairs, and ended up going through a whole maze of rooms and doors. Eventually I came into a room with a door ahead and a door to the right. The door ahead led me into the kitchen of the White Spot restaurant in the same building, so I quickly closed that door and chose the other one instead. In this room, there was another door ahead of me. I tried it, but it was locked. I turned around to come back the way I had come, but the door I came through was locked as well, that is to say locked on one side (the side I came from) but not the other (the side I found myself trapped on).
I found myself in the embarassing predicament of being trapped in a room where the only doors were locked. Fortunately, I had my cell phone and called the instructor for help. Now that I think about it, were it not for my cell phone, I probably would've been trapped there for a while.