The events in a story fit into a narrative. If I were in a story, I might be able to make especially accurate predictions by privileging hypotheses that make narrative sense. Dumbledore did this on an intuitive level, and it is the reason for his success.

If something totally crazy seemed like it was about to happen and the world was at stake, like a technological singularity was about to occur or something, and I was called to work for the team of great minds that were trying their hardest to stop the destruction of the entire universe, dropping out of high school in the process, and meeting a beautiful girl who had been living literally a few houses down from me for the last 4 years without my knowing about it, who just so happened to be doing an essay on transhumanism for her English class and would just love to interview someone who was doing work for the Singularity Institute.

Oh wait...

If I started hearing the narrator's voice

I'm not sure, considering the number of different kinds of story there are even in our world, and especially considering that entities which could create our world will probably have sorts of fiction we haven't thought of, and may have sorts of fiction we can't think of.

However, Eliezer may come up with something which would plausibly convince Harry.

• Talking animals
• Beanstalks of unusual size
• A pair of boxes, one containing $1000 ...
• Black comedy
• Poetic justice
• People living happily ever after.