We know that Harry Potter is mythical because we can ask his inventor. But what about Robin Hood, William Tell and King Arthur? Ah, how the mists of time add lustre to the legends, never allowing the prosaic to get in the way. Go back even further and things get even more etiolated: Jesus, Moses, Noah...

And I told you, Acme. I do not believe that dandelions don't grow on top of Mount Etna. I have reached the conclusion that they probably don't from what evidence there is. My conclusion is ever open to revision should new evidence come to light.   People who believe in a supernatural being do so in spite of absence of evidence. Here's the difference. If it were ever possible to prove beyond doubt that God did not exist, millions of believers would be absolutely devastated. If someone found dandelions on top of Etna, I would be surprised, intrigued and delighted.