Chapter 2 begins with the case of Ursula Mercz, a seamstress who went blind yet remained oblivious to her condition. Much like Mercz, Grant maintains that we are often blind to our own blindness—as we are unaware of the blind spots in our understanding.

Grant outlines two different psychological syndromes: the impostor syndrome and the armchair quarterback syndrome. He gives as an example Halla Tómasdóttir, a woman who was publicly petitioned to run for the Iceland presidency in 2015. Even though she had kept her investment firm afloat amid the devastating 2008 financial crisis—thus demonstrating good leadership skills—she still felt unqualified to run for public office. Grant dubs this as impostor syndrome, as Tómasdóttir had no confidence in herself even though the public did. He contrasts her with fellow presidential candidate Davíð Oddsson, Iceland’s prime minister from 1991 to 2004, who had led the country to bankruptcy. Oddsson’s unfounded confidence is a case of armchair quarterback syndrome, named after the football fans who feel they are more qualified than actual coaches and referees.

This armchair quarterback syndrome is supported by the Dunning-Kruger studies, which found that the participants who scored low on various mental aptitude tests tended to overestimate their performance in self-evaluation reports. In another one of his experiments, Dunning found that participants who were made to act as doctors quickly overestimated their diagnostic ability once they gained a little relevant experience. This points to the fact that a bit of knowledge can be more dangerous than no knowledge at all, as amateurs are prone to overestimating their expertise.

While people often think of humility as a seesaw that can teeter dangerously either toward arrogance or meekness, Grant maintains that humility centers on grounded self-confidence. He takes the case of Spanx founder Sara Blakely, who painstakingly educated herself in hosiery and patent law in order to turn her ideas into reality. He gives this as an example of confident humility, wherein one is humble regarding one’s methods yet confident in one’s ability to learn. He holds that confident humility is the key to rethinking, as one gains accurate self-awareness of one’s own knowledge and skills—as well as one’s own blind spots.

Grant then opens the possibility that impostor syndrome might actually prove beneficial to rethinking. Two former doctoral students at Wharton, Basima Tewfik and Danielle Tussing, found that medical students and professionals who exhibited impostor syndrome often performed better than their more self-assured counterparts.

In a conversation with Halla Tómasdóttir, Grant found that Tómasdóttir saw her impostor syndrome as a source of growth and humility. During the election season, her humility led her to rethink campaign strategies and utilize Facebook Live and Snapchat in order to better connect with her constituents. Although she came in second in the election results, Tómasdóttir was able to garner more than a quarter of the votes—a feat for an independent, previously unknown candidate. Grant concludes the chapter by asserting that confident humility is a corrective lens, as it helps us correct our personal blind spots and nurture healthy doubts.