I get it ALL the time. It happened to me Tuesday. I was with AllisonJoy and my friend Simone getting nails done (Not me, they were), and this lady comes up to me saying "I see you here, too?" I look at her like she had 2 heads. She said "Didn't I just see you (some name) place" I told her no. She asked if (some name) is my landlord and I said nope.
I use to get it at the hopsital, too. I would go there on our rescue and they would ask if I worked for another town's rescue, too. I told them no, but it was a twin of mine. I never met this guy to this day.
Also, there is a person that has the same bank and insurance company as I do. I use to have to make sure I tell them my whole address when I have them look up my accounts.