I was once looking for a cache and thought no one was around until I heard... "It's not there!", I looked around, didn't see anyone and continued what I was doing, then I again heard, "It's not there!". Someone came out on their balcony, I was on the pier, not far away. We had a discussion about the cache being missing, and I had to break the news to them that it was still there and I just finished signing the log!! Apparently, they (non-cacher) get a kick out of watching people look for the cache. Usually I just tell the truth in what I'm doing, since I'm not very good at making things up.