Wasn't really awkward, but noteworthy nonetheless. I was over my cousins' house one night, just to stop by and say hi during the holidays. Anyways, me and my sister were sitting at the kitchen table. My dad, his sister (our aunt) and our mom were in the other room. Only one of my cousins was home that night (20, 17, and 15, and all girls). The 20 and 17 year old were out, while the 15 year old was upstairs and had other friends over (she's insanely shy). Because I don't have the best eyesight, I have a tendency of not being able to identify people from afar. The door opens, and I think it's my 17 year old cousin (blonde hair, kind of pale, roughly similar height). Little did I know, it was one of the 15 year old's friend. I waved with a bit too much enthusiasm and said hi (you know, the holidays), and she did the same, even though she had no idea who I was. It wasn't until she actually walked across that I realized it wasn't my 17 year old cousin. That was probably for the better, because some mistakes don't need to be corrected right away. Thankfully, we both played it off as not weird for a first encounter, but it could've been.