The Three Peasants

Pg. 518
"By this time Don Quixote had kneeled down next to Sanco and looked, with startled eyes and confused vision, at the person Sancho was calling queen and lady, and since he could see nothing except a peasant girl, and one not especially attractive, since she was round-face and snub-nosed, he was so astounded and amazed that he did not dare open his mouth."

I found this passage interesting, and perhaps it defends DQ's sanity. He creates his own reality, but does not believe the patronizing fantasies that Sancho is feeding him. Though, much earlier in the novel, he confused as promiscuous chambermaid (at the inn/castle) to be a beauteous maiden, though her breath was rank. (One of the funniest parts, in my mind). It seems that DQ is the only one capable of inventing his own vision of reality (which is appropriate). Like a little kid with an imaginary friend, you can never tell the child where his/her friend is. If you do you are terribly mistaken and you're probably sitting on it