Garrison Keillor Beat You There

Barking Up the Wrong Tree has a post on the errors in people's self-assessments:

In general, people’s self-views hold only a tenuous to modest relationship with their actual behavior and performance. The correlation between self-ratings of skill and actual performance in many domains is moderate to meager—indeed, at times, other people’s predictions of a person’s outcomes prove more accurate than that person’s self-predictions. In addition, people overrate themselves. On average, people say that they are ‘‘above average’’ in skill (a conclusion that defies statistical possibility), over- estimate the likelihood that they will engage in desirable behaviors and achieve favorable outcomes, furnish overly optimistic estimates of when they will complete future projects, and reach judgments with too much confidence. Several psychological processes conspire to produce flawed self-assessments.