Most Helpful Guy
there are actually studies about this, I'll try to find the links, but I'll post what I can remember
okay, speaking in terms of a 1-10 scale one being ugly and 10 being hot, most people out there rate their own attractiveness at 7 on average. but wait, 7 is above average. the average should be around 5. because that's the median, smack in the middle of what's ugly and pretty. you can do the math, how can the average person be rated a 7, if the true average must be at 5? that would be mathematically impossible right? that would mean that the vast majority of people you see are good looking people and we all know that this just isn't true. this means that people rate themselves higher than they actually are.
and you do look different in mirrors because we can only see ourselves in the mirror. the mirror indeed flips the image, so the self we are seeing isn't actually our true selves because what our friends and family see is an un-flipped image of us. that being said, if we were to see ourselves through our friend's eyes, we would look different than how we think we look for two reasons. the first one being that our eyes are fond of things that are more familiar to them, and guess what we see everyday in the mirror! and the second reason is that their perceptions and personalities are just plain different than ours, so it's only natural that they don't think we look the way we think we look.