Have you ever seen a doppelganger of yourself? Family members don't count.
When I started working here, I kept hearing that I was the spitting image of this girl in another department and was confused for her a couple times. I finally met her about a month later, and aside from both of us having dark hair and glasses, I didn't see it.
The closest I've come was some girl on facebook - a friend linked me to her profile picture because at the specific angle she was looking at the camera, I totally would have believed that was me too.