Bet-David makes a distinction between knowing that you might be wrong and genuinely engaging with the possibility. Most people will acknowledge intellectually that their views could be mistaken. Far fewer take the active steps required to find out whether they are. He argues for what he calls aggressive curiosity: the habit of seeking out the best argument against your current position, the most capable practitioners of approaches you have dismissed, and the evidence that most directly challenges the conclusions you are most comfortable with. This is different from simply being open-minded. Passive open-mindedness waits for contradiction to appear. Aggressive curiosity goes looking for it. Bet-David applies this specifically to beliefs about what is possible. Most people have never seriously tested the limits of what they are capable of. The beliefs they hold about their own ceiling were formed in contexts, schools, families, early careers, that were not designed to reveal those limits. The limits that feel most real are often the ones that were never tested. The discipline of challenging your thinking is therefore also the discipline of challenging your self-concept. Finding out that the ceiling you assumed was real is actually a paper wall is one of the most practically important discoveries available to any ambitious person.