That was so beautifully and accurately put. I really am wholeheartedly impressed with that way of explaining who he is.
In fact, I think that’s the answer to Mycroft’s question in A Scandal in Belgravia: “My brother has the brain of a scientist or a philosopher, yet he elects to be a detective. What might we deduce about his heart?”
^ All of this. Even when reading the stories we’re all familiar with, that’s how I’d describe Sherlock Holmes. BBC Sherlock’s take on the character, I think, only emphasizes this further. He doesn’t understand it—and maybe a great part of him doesn’t want to, because it gets in the way of the facts and the facts are what he wants.
And yet, if he hadn’t any sort of grasp of what it really means to be human and to have a heart, how could he make the deductions he does? He does know how people work. He knows how the heart works. There are factors that contribute to what make the crimes Sherlock solves happen to begin with—anger, remorse, pain, family, friends, reality, humanity. He knows all these—he just doesn’t always understand, especially when they apply to him. However, for all the “useless” information Sherlock “deletes”, he is still human. What he recognizes in others through his deductions are things we recognize as viewers in him (that John recognizes in him: “You were the most human, human being I’ve ever known … “). He just doesn’t recognize it himself.