In "The Count of Monte Cristo," a prison guard advises a captive to avoid fixating on unattainable dreams, warning that such obsessions can lead to madness. This suggests a deeper theme of the novel, where characters grapple with hope and despair in the face of insurmountable challenges. The quote underscores the dangers of dwelling on the impossible.

Dumas illustrates how unrealistic expectations can consume an individual, leading to a state of mental turmoil. The advice given reflects a pragmatic approach, emphasizing the necessity to maintain mental resilience and focus on achievable goals rather than getting lost in dreams that may never become reality.