A warning against overoptimism:
"One of the benefits of an optimistic temperament is that it encourages persistence in the face of obstacles," [Daniel Kahneman author of Thinking, Fast and Slow] explains. But “pervasive optimistic bias” can be detrimental: "Most of us view the world as more benign than it really is, our own attributes as more favorable than they truly are, and the goals we adopt as more achievable than they are likely to be."
For example, only 35 percent of small businesses survive in the U.S. When surveyed, however, 81 percent of entrepreneurs assessed their odds of success at 70 percent, and 33 percent of them went so far as to put their chances at 100 percent. So what? In a Canadian study Kahneman cites, 47 percent of inventors participating in the Inventor’s Assistance Program, in which they paid for objective evaluations of their invention on 37 criteria, "continued development efforts even after being told that their project was hopeless, and on average these persistent (or obstinate) individuals doubled their initial losses before giving up." Failure may not be an option in the mind of an entrepreneur, but it is all too frequent in reality.
The Dish 