It's honestly probably the core reason that I try to avoid groups of people and gatherings. When people are there, they are more likely to look at you. If more people are looking at you, you're much more likely to be noticed when you inevitably do/say something incredibly stupid. Now, I consider myself at least reasonably well-spoken, but i'm a total clutz and there's at least two or three moment a day in which I wish I was an alien (or, retarded) so I would have an excuse for not knowing how to do perfectly common things. (RECENT EXAMPLES: How to cut a baguette, How to operate a corkscrew).
And, so in a desperate attempt to avoid embarrassing situations, I avoid almost *all* situations. That can't be very socially healthy, I would imagine.
People are scary!