Most personally convincing reasons you don't believe.

[robvalue]

"Here's a story book."

"OK."

"This book depicts actual events."

"No, it doesn't. Not the obviously made up bits, anyway."

"Can you prove it doesn't?"

"I don't need or want to disprove fantastical elaborate conspiratorial unfalsifiable assumptions."

"But can you prove it doesn't?"

"No."

"See?"

"No. All I see is you making wild claims about an arbitrary story book. Do the same thing with another book."

"No."

"Why not?"

"Because the other books are fiction."

"Can you prove they are fiction?"

"...."