Actually, it might be as simple as Doyle not being able to portray Holmes exactly the way he wanted to portray him due to the prejudices of the time.
By putting the TV version of Holmes in my mind while reading "The Hound of the Baskervilles", it changed the overall feel of the story (I had already read half of the book before, but hadn't finished it). I couldn't believe that a somewhat "normal" person could have these incredible deductive abilities, which made the stories and subsequent movies seem completely unrealistic. But what about someone with specific mental issues? Autistic? Idiot-Savant? Bipolar disorder? A combination of disorders? It's suddenly all made sense now!
Today, we know that people with certain mental difficulties can also possess some pretty incredible mental abilities. Doyle may have been aware of this, maybe even a sufferer/beneficiary himself. But to reveal these mental difficulties during the Victorian era could have been disastrous for the character, and possibly for Doyle himself.
It was the mention of the solar system in the book, and how it was interpreted in last week's episode of the show that allowed me to finally make the connection. After nearly a century of misinterpretation, we might be finally seeing Sherlock Holmes depicted exactly as Sir Arthur Conan Doyle had originally envisioned him, but which he may have never been able to fully disclose due to the prejudices of the time.