Ingorance is bliss and a lot of people are smiling!

I've been in a pretty good mood today all in all. While I was out for lunch I stopped by the bank. A man was walking past me with his work shirt on with his name on it. So I said hey Greg like he was a long lost friend and he stood there and tried to make idle chit chat with me, he had no clue that I didn't know him from Adam's house cat. Then I am standing in line at the bank waiting forever and this young lady was standing behind me and made a comment about how longit is taking. When I turned around, the first thing I seen was her nametag, she worked at holiday inn, so feeling cheeky I said "well hey Nikki" and again she never realized that I had no idea who she was. At this point I was trying my best not to laugh and it was my turn at the teller, so I walked up there and again said "hey Cindy", she just looked at me strange and said hi. Are people just not aware that they are wearing nametags?