Never locked myself out, but thought I did. I returned from a trip to London and thought my keys were in the larger of 2 carry-on bags, which was put on the next day's flight. Before we left London airline employees told us that would happen and I put my keys in my smaller carry-on. Well, when I arrived in Baltimore (about 40 or so miles from my place) I had forgotten what I had done. I asked my friend who had picked me up at the airport if I could stay over night. I also needed a ride back to the airport the next day. He agreed. Went back to the airport the next day. Checked my bag ---no keys. Then I remembered what had happened. I think my friend took the news surprisingly well.