On a related note, my friends and I had a discussion concerning "what would our ages be SOLELY based on our looks?""You look 15." (I'm 22, around 100lbs, and have a lot of freckles, in their defense...)
My internal voice: "You look ugly."
My real voice: "Uh, thanks?"
Also, I sell my own artwork and dreamcatchers and sometimes hear "well I could make that for x amount" or "it can't be that hard to make." At first I used to be nice about it, now I'm just like "then go make it yourself."