Soooo... the brain, basically.
This sounds like a research-heavy one, but I'm going with it anyway because the other ones I have queued up are too awful to contemplate. I'm choosing perplexing over terrible this week; I hope that's okay.
I think originally I wanted to write about ESP and telekinesis and I thought the brain's LATENT ABILITIES might be a good psuedo-scientific way into those.
You know, I could always just write a story about someone who keeps forgetting stuff. Forgetting is also innate to the brain. You can't tell me it's not!
Anyway... time to get brainy.