Here's why:
* Limited Perspective: The narrator is Dr. John H. Watson, Sherlock Holmes's close friend and companion. We see the story through his eyes, meaning we only know what he knows, experiences, and is told. We don't have access to the thoughts of other characters unless Watson is specifically informed.
* Focus on Observations: While Watson is a keen observer, he doesn't always fully understand Holmes's deductions. The narrator often describes Holmes's process and conclusions, but doesn't always explain the reasoning behind them.
* Unreliable Narrator: In some cases, Watson can be a somewhat unreliable narrator. He can be surprised by Holmes's deductions and sometimes doesn't grasp the full complexity of the situation. This adds to the intrigue and keeps the reader guessing along with Watson.
In summary, the narrator in Sherlock Holmes stories is a limited, first-person narrator who provides a specific perspective on the events. This creates an engaging and interactive reading experience, where the reader is encouraged to piece together the puzzle along with Watson.