I couldn't find the old thread with the post from the former Cellar member. But this is a great post from his website:
The Total Perspective Vortex
Most people think of the "mentally disordered" as a delusional lot, holding bizarre and irrational ideas about themselves and the world around them. Isn’t a mental disorder, after all, an impairment or a distortion in thought or perception? This is what we tend to think, and for most of modern psychology's history, the experts have agreed; realistic perceptions have been considered essential to good mental health. More recently, however, research has arisen that challenges this common-sense notion.
In 1988, psychologists Shelly Taylor and Jonathon Brown published an article making the somewhat disturbing claim that positive self-deception is a normal and beneficial part of most people’s everyday outlook. They suggested that average people hold cognitive biases in three key areas: a) viewing themselves in unrealistically positive terms; b) believing they have more control over their environment than they actually do; and c) holding views about the future that are more positive than the evidence can justify. The typical person, it seems, depends on these happy delusions for the self-esteem needed to function through a normal day. It’s when the fantasies start to unravel that problems arise.
continues:
http://www.damninteresting.com/?p=864#more-864