You know that huge zit you're obsessing over? Stop worrying. According to this study on a psychological phenomenon called the "spotlight effect," people don't notice your self-perceived flaws as much as you think they do (if at all!).
College students were asked to wear t-shirts plastered with images of "embarrassing people" like Barry Manilow and Vanilla Ice (which sound rather awesome to us), and walk into a room full of people. The students thought the others would notice their shirts much more than they actually did. But if students were given time to get used to wearing the embarrasing t-shirts, they thought fewer people noticed them.
It seems that our self-perception stems from how much we're thinking about our looks and actions: the less we're thinking about it, the less we believe that others are thinking about it.