Magic and Fantasy?

Ever have the strange thought that "reality" isn't actually reality?

I guess I do this all a lot. I always think "what if this is all a dream?" "what if I am imagining all of this" and I'm always questioning what is real and what isn't around me. But to get to the magic part, I've started re-reading harry potter for the 4892482934th time, and of course keep thinking how cool it would be to be real. But how do we know it isn't real? I mean, JK Rowling could just be a wizard trying to make some muggle money after she lost it all in the Gringots Battle for the Lestrange Vault. Okay, so it probably isn't true, but isn't a funny thought to think?