I had three similar weird experiences this week. The first two happened at Walmart. I was walking down the aisle, and a woman came around the corner and looked at me and in a happy, excited tone said, "Hey girl!" I think she thought I was someone else, but then realized she didn't know me, so turned and went a different direction. I probably wouldn't have thought much about that, but about 3 seconds later, a woman and her husband also came around the corner and she excitedly said, "Hi!", before also realizing I wasn't someone she knew.
Then I was standing in the Wilkinson Center at BYU, and a man and his wife passed by me. He looked at me, then kept walking. But then he looked back at me like he thought he knew me. Then he kept walking. Then he looked back again, like he MUST know me, but then kept walking. A third time he looked back, but finally decided he didn't know me and kept walking.
I would attribute this to my fly being down or something, but that wasn't the case. Weird, don't you think?