Onward to the post!
Sherlock has his faults. His addictions. His ambitions. His loves. Sherlock has a very strong personality and he's not one to half-ass two things. He whole-asses one thing and won't stop until he's content.
But it's that same drive that creates the biggest dangers for him. So many of the times he has been hurt, and/or endangered, it was because of one of his passions. His.
It seems to me that everyone is always blaming Moriarty. Or Moffat. Like all the time. No one ever takes a look at Sherlock's role in his life. Moriarty may be the good old-fashioned villain in our fairy tale, but Sherlock has his own internal villains to deal with.
Sally Dono-blech once said, "One day, we'll be standing around a body, and Sherlock Holmes will be the one who put it there."
And it was. It was Sherlock who put himself on the sidewalk. Was he under duress? Yes. Did he do it for the sake of Jawn and the Baker Street Boys? Yes. But in the end, it was Sherlock. It was his love for them--that inevitable disadvantage--that ended him.
Sherlock is Sherlock's end.
Sherlock is Sherlock's nightmare.
Sherlock is Sherlock's worst enemy.