A plan is only a scenario, and almost by definition, it is optimistic... As a result, scenario planning can lead to a serious underestimate of the risk of failure.
Doubts are suppressed by groups... But remember that the internal incentives that shape how the group perceives risks and rewards may be very different from the reality of the risks and rewards in the external marketplace. Those incentives can distort risk perception.
Lucky risk takers use hindsight to reinforce their feeling that their gut is very wise. Hindsight also reinforces others' trust in that individual's gut.
There's a tendency to look at investments in isolation. Investors focus on the risk of individual securities.
