Placing human history on a 24-hour scale, that's less than two seconds. I doubt anyone hasn't. This is a vast topic, so for now I will focus on overconfidence. In general, an abundance of confidence is a wonderful thing. It gives us higher motivation, persistence, energy, and optimism, and can allow us to accomplish things that we otherwise might not have even undertaken.
Confidence also contributes a great deal to happiness.
The average guesses were 27.4 days, 33.9 days, and 48.6 days, respectively. The actual average turned out to be 55.5 days. Mutual fund managers, analysts, and business executives at a conference were asked to write down how much money they would have at retirement and how much the average person in the room would have. Perhaps more surprising than the degree of overconfidence itself is that overconfidence doesn't seem to decline over time. After all, one would think that experience would lead people to become more realistic about their capabilities, especially in an area such as investing, where results can be calculated precisely.