I couldn't find my phone. I decided to ring it on my housephone to hear where it was ringing.
This turned out more complex than I imagined. It seemed to be ringing somewhere behind me but, when I turned round and went over to the outside of the room, it rang from behind me again. Everywhere I turned the phone was somewhere behind me but I wasn't sure where.
It took me far longer than it should have done to realise it was in my back pocket...