Looking for a book where it is set in a different reality and the main character a boy can go into that reality or place.

He has the power to do so. He has some sort of magical ability. I can barely remember the plot I read it as a kid I remember being intrigued by the author who talks like the reality is real. In the back of the book where they describe the author they talk about the author telling everyone about how the magical world from their book is real. I hope someone knows what I’m talking about.