. . . is humility. It is the ability to say; “I may be wrong”; “I’m not above average”; “I’m not perfect”. There is scope to improve.
Our near and dear ones help to keep our egos inflated. As a result, we think we are extra special, and the base rate do not apply to us. We are the exception. In fact, we are ordinary. There are very few who are indeed very good, and they get there because they keep questioning their beliefs, their status quo and keep the iterative process alive. They always improve.
And unless you have the gravitas to accept how normal and fallible you are, you will never be able to learn. Learning involves starting from the position of being aware of your blind spots. And people who agree they have blind spots are the ones who also know they are incomplete, do not know everything and hence the need to learn and better themselves.
People with know it all attitude, always suffer from confirmation bias, never keep in touch with the base rates, as a result, are off the mark when it comes to their capabilities and competence.