Like Lear, we can learn to see better, not just because our brain changes but because we do. As all wisdom does, seeing starts with simple questions: What could I know, should I know, that I don’t know?
From "Wilful Blindness: Why We Ignore The Obvious" by Margaret Heffernan
(quoted in multiple other books)
Can anyone tell me why in the last question, the "that" is necessary, what if replace it with "and"? so the sentence becomes "what could I know, (what) should I know, and (what) I don’t know?"