It's rarely worth it to condense your knowledge into a specialty.
You should be broad in your knowledge. Holmes says that you should have a clean "brain attic," but he's also a walking encyclopedia of knowledge. He reads incredibly broadly—he reads about art, music—things that you would think have no bearing on his detective work. I think that's an important lesson that we can take. It's bad to overspecialize, and we should try to remain as curious about all the different types of things you want to learn. -- Konnikova