They emphasise that critical thinking is meaning that you should think for yourself, as opposed to reading a book a reiterate what a book has told you word for word. To think about what you are looking at, is it fact or opinion? what is the context of the matter? etc. I now understand the idea that critical thinking can become better and better by the exposure to more context, helps create a greater analysis etc all of which ties into having a better understanding.
The Authors are using a persuasive narrative as they try convince us the reader, that we should expose ourselves to the ideas of critical thinking and broaden our horizons. They use the pronouns of you, mainly as they direct the attention completely to the reader as they try to persuade them of their point. They position themselves on your side as they speak personally to you directly. I personally find that their style of narrative speaks to you very directly and makes you feel of significance, and therefore feel as though you are capable of doing what they are asking you to do. They have a simplistic style of writing which I enjoyed reading. They direct speaking and simplistic style of writing as well as the ideas behind it created a enjoyable read.