It's a mystery. A man's at odds to know his mind cause his mind is aught he has to know it with. He can know his heart, but he dont want to. Rightly so.
The quote reflects the complexity of self-awareness and the struggle of understanding one’s own thoughts. The man grapples with his mind, which presents a paradox: the very tool he uses to comprehend himself is the same thing that creates confusion. This indicates an inherent limitation in self-perception and the challenges of introspection.
Furthermore, the statement highlights the distinction between the mind and the heart. While one can have a deeper understanding of emotions and feelings, this knowledge can be uncomfortable or unwanted. It suggests a degree of avoidance when it comes to confronting one's true feelings, a theme prevalent in McCarthy's work.