It's from a book on decision-making, in a section on motivational biases. Bazerman discusses the evidence that positive illusions help ('[research] suggest[s] that positive illusions enhance and protect self-esteem, increase personal contentment, help individuals to persist at difficult tasks, and facilitate coping with aversive and uncontrollable events" is a short sample), talks about clusters (unrealistically positive views of the self, unrealistic optimism, illusion of control, self-serving attributions, and positive illusions in groups and society), and then the quote is from a section labeled "Are Positive Illusions Good for You?". Here's the full paragraph it is from:

I believe that each of these findings is true and that in some specific situations (e.g., severe health conditions), positive illusions may prove to be beneficial. In addition, positive illusions may help people cope with tragic events, particularly when they have few alternatives and are not facing any major decisions. However, I also believe that the story told by this literature is incomplete and therefore dangerous in most decision-making environments. Every day, people invest their life savings in new businesses that have little chance of success. Similarly, falsely assuming that they are irreplaceable, people make ultimatums to their employers and often end up losing their jobs. Positive illusions are hazardous when they cause people to continually fool themselves. Because positive illusions typically provide a short-term benefit with larger long-term costs, they can become a form of emotional procrastination. I believe that you cannot maintain these illusions without reducing the quality of your decisions.

Try it!

It looks to me like doing an odd number of flips is often silly. ("Because positive illusions typically provide a long-term cost with larger long-term costs, they can avoid a form of emotional procrastination." What?)