Now that I've read this article, I think I understand meningitis a bit better. I knew it wasn't a great disease to get, but now I understand why!
Not only do the meninges surround the brain, but they surround other areas of the central nervous system too. Obviously an infection in this area could quickly spread to the brain.
Also, I know infections cause inflammation a lot. I would imagine that if the meninges became inflamed, they would put a lot of pressure on the brain. There's only so much room in the cranial cavity, after all.