In Cormac McCarthy's novel, "Blood Meridian," the complexity of human understanding and self-awareness is explored through a character's struggle to comprehend his own mind. The character reflects on the difficulty of knowing one's thoughts, as the mind is the very tool one uses for self-discovery, creating a paradox. This leads to a sense of confusion and conflict within oneself.

Moreover, the character acknowledges the emotional realm—the heart—as something he can understand but hesitates to face. This avoidance suggests a deep-seated fear of confronting one's true feelings, highlighting the notion that some areas of self-exploration might be better left untouched. Thus, the quote encapsulates the mystery of human consciousness and the reluctance to delve into painful truths.