Author Adam Grant argues that intelligence is not just a skill for thinking but an ability to rethink and forget what you've learned before. Cognitive flexibility is the art of ignoring our instincts, even though we tend to trust our gut feelings. Rethinking and questioning ourselves helps us stay relevant in an unstable world.

Being a preacher, prosecutor, or politician is like falling into the trap of attacking dissenting views, defending your opinion, or simply winning an argument. Grant insists that having a change of heart isn't a weakness, it validates your intellectual development. Scientists live to comprehend the limits of their knowledge, and we can learn from them to improve our thinking process.

Overconfidence is a trait typical of people with Armchair Quarterback Syndrome. The author suggests that we teach ourselves to be modest, but in a self-assured way. Not only does confident modesty allow us to recognize our flaws, but it also enables us to work at overcoming them.

When someone points out that we are wrong, many of us react angrily and fearlessly defend what we believe. Psychologist Richard Grant says we should learn to detach our present selves from the older versions of ourselves. He suggests that we develop a system of values instead. This will allow us to change our beliefs while staying true to our values.

There are essentially two types of conflicts:

1. Task conflicts. They occur when members of a specific team decide who should tackle a problem, what should be done and how, etc. This type of conflict is constructive because it prompts the seeking of creative solutions.
2. Relationship conflicts. These occur between people. Often these conflicts are detrimental because they impact interpersonal relationships negatively. However, if the parties to an argument show respect for one another, they may end up with a higher degree of compassion and cooperation.

Our society tends to regard pliability, or a tendency to avoid conflicts, as a positive trait. People who are not afraid to show disagreement with our opinions actually push us forward. They help us evaluate our abilities and find ways of improvement.

To help others rethink their beliefs, Grant recommends avoiding overwhelming rational arguments like those a logic bully would use. Even if you are correct, the other party will be left feeling bitter. A more effective approach is to find common ground and express curiosity by asking questions. These questions let the other person draw their own conclusions, and this is more powerful than crushing them with logic or reason.

It is natural for people to seek affiliation with some team or side in a rivalry, but once we become members of this team, we expose ourselves to polarization. When rivals attempt to challenge our views, we respond with hostility. In the process of bonding with teammates, our opinions get entrenched even deeper.

Three exercises to help us rethink our rivalries:

1. Find a common identity with your opponents.
2. Spread empathy toward the entire group after applying it to a single member.
3. Understand that our stereotypes are arbitrary.

The three pillars of motivational interviewing are:

1. open-ended questions

2. reflective listening, and 

3. encouragement to change 

An interviewer doesn’t try to persuade or advise. Instead, they act as guides to help lead an interviewee to a beneficial conclusion or decision. The main trait of motivational interviewers is that they don’t leave a know-it-all impression. Rather, they induce their interlocutors to feel smart.

Grant builds on this point and states that preaching a point with passion is not an effective way of persuading others. Being able to recognize the complexity of an issue instead will make you far more credible.

For example, when talking to conservatives, you shouldn’t be pushing for caps on vehicle emissions to tackle climate change. Instead, frame the idea around the economic benefits of green-tech innovation. This approach better accounts for the complexity of the issue. Simultaneously, it lets you engage your audience.

Knowledge isn’t frozen in time. Things we deemed correct 20 years ago may now seem outdated. When we acquire knowledge, we either trust what we learn or retain a skeptical attitude. Skeptics focus on things that are left out instead of things that are in focus. This approach helps keep their minds open and promotes rethinking. 

Skeptics don’t trust the new information they learn. They will take their time to establish the credibility of these newly learned "facts" before they can believe them. Deniers, on the other hand, reject anything they learn from external sources. They believe that only their opinions are true. They normally assume the role of a prosecutor, preacher, or politician, whereas a skeptic is a prime example of a scientist.

Collective rethinking is also about changing organizational cultures. A culture of collective rethinking encourages psychological safety, for instance, by allowing team members to take risks without fear of punishment. In these types of teams, employees are more willing to report problems. The team can change its mind collectively based on the information obtained from its mistakes. 

It’s human nature to make plans. We have visions of where we want to live, who we want to marry, or how large we want our family to be. With all of this in mind, we tend to set boundaries. In the best-case scenario, they help us achieve our goals. More often, however, they give us tunnel vision and prevent us from seeing better possibilities.

What’s even worse, if our plan doesn’t go the way we envision, we usually start spending more time and resources to fix things. Alternatively, we could ask ourselves a simple question: “Was this a good plan?” To question your plan instead of executing it at any cost is the essence of rethinking. Determination to succeed is great, but it has the opposite result if it leads to mental rigidity.