Never will man penetrate deeper into error than when he is continuing on a road which has led him to great success.This is a dual truism arising from faulty forecasting and overconfidence. Specifically, a run of success tends to encourage a belief that we have conquered failure and setbacks and we forecast into the future the current trend line. Thus are all bubbles created whether internet stocks or real estate. Forecasted catastrophe's likewise. All my life we have been at peak oil and then some new technology comes along opening up previously inaccessible reserves. Despite all our knowledge and experience, there are structural quirks that encourage straight line forecasting to the detriment of accurate forecasting.
The second truism arises from knowledge confidence. We are successful. We explain that success based on some set of actions or circumstances; usually some set of actions we took given some particular circumstances. Typically, our narrative explanation for success emphasizes our own contribution and minimizes circumstance and luck (Nassim Nicholas Taleb cover's this ground in Fooled by Randomness). Our explanation may be more or less accurate but the longer the success continues, the more confident we are in our explanation regardless of the truth. Our search for accurate explanations slackens with out confidence.