I think when I am comfortable with what I know, I used to defend it so I can prove myself is right.
I think it is also important to allow what I know to be challenged and keep an open mind about it.
I think one of the problems I developed in the past years was to search online to support my idea. Instead, it is better for myself to search for ideas to disagree with mine, in the process, I can evaluate if I am right or I need to adjust my idea.
Anyway, this is a good book. It challenges my way of thinking and always allow myself to be comfortable to be wrong.