<Snipped quote by Dynamics>
Because that's where the concepts of things are. Imagine that in the book, the word "blue" was written. We know what blue is, and that blue now exists in the story and physically on the page, right? But now imagine that the definition of the word "blue" was changed to that of "red." Suddenly, everything that was blue is still blue, physically the same, but is defined differently, changing the meaning of what's written. That's how the powers of the Codex work, they change concepts. So in this case, what I believe happened is that the definition of "me" in the dictionary was amended to include the phrase: "Only exists within a certain dimension," to keep with the analogy.
Okay, but that still doesn't change the fact that you can get something out of this place.