Trisha Sindiong's Key Ideas from Think Again
by Adam Grant

• We often prefer the ease of hanging on to old views over the difficulty of grappling new ones.
• Questioning ourselves makes the world more unpredictable
• Reconsidering something we believe deeply can threaten our identities, make it feel as if we’re losing a part of ourselves.

It’s when we lack competence that we’re most likely to be brimming with overconfidence.

From Wikipedia :

It is based on the idea that poor performers have not yet acquired the ability to distinguish between good and bad performances. They tend to overrate themselves because they do not see the qualitative difference between their performances and the performances of others.

People who scored the lowest in logical reasoning, grammar and sense of humor had the most inflated opinions of their skills.