All the time. ;D
Well okay, in all seriousness.. online it happens quite frequently. XD IRL it's only happened.. 3 or 4 times, and each time I was rather surprised. Honestly, looking at me, I'm not sure how anyone could be confused, but the few times it did happen I figure my hair style was responsible, or maybe however I was dressed at the time. :/ I guess.. still not sure.