One thing I love about Borges is that because he is a writer of short stories--and because those short stories are many in number--he can create his own reality. Let me explain.
In any one book, the author can create a world the way he/she wants to. Tolkien created whole languages, not to mention many different creatures, humanoid species, and physical landscapes. He created his own rules for his particular world. Every writer of fiction--arguably every writer, period--creates his own worlds.
What is unique about Borges is that he creates his own reality. He has different worlds in each of his stories. Some worlds are just like ours. In others, the worlds are governed by secretive elite groups; in others, the physical world itself is just one big library, etc. But connecting between these worlds are common themes and common entities.
He's an example: Axaxaxas mlö. I first saw those made-up words in Borges' "Tlon, Uqbar, Orbis Tertium." They represent part of the sentence, "Upward behind the onstreaming it mooned" in the language of Tlon. (I don't know what that sentence means either.) I ran into the words again, though, in another of Borges' short stories, "The Library of Babel." In that story, it is the title of a book which no one can read, but which is admitted to be written in a legitimate language that no one understands.
I did a total double-take when I saw those words again. "Sneaky, Borges, sneaky," I thought. I think he's making the statement that although the people in one of the worlds he created didn't understand the language, people in a different world he created did, and somehow the words still have meaning in both worlds, strictly because they had meaning in one of the worlds. Crazy.
So Borges does that; he puts the same words, motifs (especially mirrors and mazes), and ideas all over in his different stories. The worlds he creates are many, but the reality is the same--it is the reality of his mind, and I meet Borges when I find the common threads in his worlds and develop an understanding of his reality.