Why is Utterson so obsessed with images Enfield's story about Hyde that he cannot sleep?

Utterson is obsessed with the image of Hyde because it resonates with his own fears and curiOSity about the mysterious figure. The story adds to the intrigue of Hyde as a sinister and troubling character, sparking Utterson's sense of duty as a lawyer to investigate further. This obsession reflects Utterson's deep concern for his friend Dr. Jekyll and a desire to understand the connection between Jekyll and Hyde.