An excellent cautionary story about being overconfident, especially about financial decisions.

Nobel laureate Daniel Kahneman writes persuasively about people's tendency to believe what they want to believe rather than what evidence may indicate. Although a psychologist, Hahneman has contributed greatly to the field of financial decision making.
http://www.nytimes.com/2011/10/23/magazine/dont-blink-the-hazards-of-confidence.html?_r=1&src=me&ref=magazine
from the NY Times