The guides of the Everest expeditions often boasted that they could guide anyone with average fitness to the top of Mt. Everest. They were so confident that they ignored the 2:00 return to base rule and paid the ultimate price.
In a poll taken of teen drivers, 93% indicated that they were better than average drivers.
Statistically, only 50% can be better than average. A similar poll asked start-up entrepreneurs how likely they are to be successful. Ninety percent said their business would succeed. The real figures are more like 50%. I have seen many a retail entrepreneur who had a successful launch with their first store, and then figured they could replicate the same business model and open a second location, only to discover it is not that easy and lose both stores.
Are you guilty of an overconfidence bias?