I have always believed that scientific research is another domain where a form of optimism is essential to success: I have yet to meet a successful scientist who lacks the ability to exaggerate the importance of what he or she is doing, and I believe that someone who lacks a delusional sense of significance will wilt in the face of repeated experiences of multiple small failures and rare successes, the fate of most researchers.

An investment said to have an 80% chance of success sounds far more attractive than one with a 20% chance of failure. The mind can't easily recognize that they are the same.

Individual investors predictably flock to stocks in companies that are in the news.

Knowing the importance of luck, you should be particularly suspicious when highly consistent patterns emerge from the comparison of successful and less successful firms. In the presence of randomness, regular patterns can only be mirages.

Most things that couples disagree upon aren't worth more than a day's combat.

In essence, the optimistic style involves taking credit for successes but little blame for failures.

An executive might have a very strong intuition that a given product has promise, without considering the probability that a rival is already ahead in developing the same product.