Who's Watching?

We sometimes think we are invisible when we are among strangers at an event or venue. Do we act differently when we think no one is watching? I've decided we should always assume that someone is watching. Recently a friend was leaving a big box store as Edgar was arriving. He spotted her because she was walking to her vehicle, but she didn't notice him because he was camouflaged in one of the many arriving SUVs. There was nothing noteworthy about the missed opportunity to visit. It was just a reminder to me that we never know what others may casually observe without our knowledge.