Our eyes do an AMAZING job of correcting visual mistakes, asymmetry especially. I learned this when I first started to paint, I would do something I thought looked okay, but then I'd comeback a few days later and realize it's wack and full of mistakes. Same thing applies to our faces, we're so used to looking at ourselves in the mirror that we get used to -and eventually disregard- some of our more subtle flaws. So when you first look at yourself in a mirror image it can be really jarring. The thing is, this same type of correction applies to how other people look at you too, so even though you notice your flaws when you first see yourself in the correct perspective, rest assured that the people who see you everyday are used to how you look, and don't really notice your flaws either, they just see you for the beautiful you that you think you are.