~ When John and Mary's neighbor, Kate, comes about her junkie son, Issac, and John asks if Issac is her husband, it's a nod to the books. In The Man With the Twisted Lip, Kate's husband is named Isa Whitney. 

~ According to Whitepages.com, there are 34 people named Sherlock Holmes in the USA. 

~ Sherlock Holmes is the most portrayed human literary character in film and TV. If your counting half-humans, he's the second, the first being Dracula. 

~ About 1,000,000 people Google 'Sherlock Holmes' every month.

~ There's a Sherlock manga in Japan.

~ Sherlock technically isn't a sociopath. He's too caring, empathetic, and aware of his own faults to be a sociopath. He most likely is autistic with ADHD.

~ Mycroft only appeared in two of the books, but he appears in nearly every BBC episode.

~ Benedict was the only actor asked to audition for the role of Sherlock. 

~ The pen toss in The Blind Banker was done on the first try but, due to troubles with the camera, had to be shot again. It took three more tries to get it right. The trick was having Benedict look into a mirror to know when to catch it. 

~ Martin Freeman has an "I Don't Understand, I Still Don't Understand" T-shirt.