Astral Projection and Fiction?

Out of curiosity, were they presenting this idea as fiction, like just a what-if, or more seriously, like using astral projection methods to produce some kind of controlled hallucination?

Although, now that I'm thinking about it, the idea of fictional worlds really existing, but on some different plane of existence is a cool idea. It would make for a good book.

If I were visiting fictional worlds, I would probably go into this little video game called "Flower." It's all naturey and pretty, and I'd use it as a quiet little "happy place." (Do a google image search for "flower ps3" and you'll see what I mean.)

If I wanted someplace more interesting, I'd head over to Narnia. Those books were a big part of my childhood, and have always had a special place in my heart.