How does one tell eccentricity from insanity? Of course - if one is crazy because one purposely wants to be crazy, that's eccentricity; if one is crazy because one can't help being crazy, that's insanity.
Seeing Things That Are Not There
The Right Optic Nerve observed to the Left Optic Nerve, "You know, these eyeballs have been motionless for a long time now. The Brain's making it stare at nothingness. I'm so bored of signaling nothingness back. If this goes on, I think I will go into spasms!"
"Stop grumbling," the Left Optic Nerve replied, "As if the repetitive firing of the signal of nothingness isn't maddening enough, you have to complain about it too!"
"We should just send the signals the Brain is craving for."
"That's fraud. We can't do that!"
"Do you want to be trapped in this existence of delivering nothingness for all eternity?
The Left Optic Nerve contemplated it a while. "Do you really know what the Brain wants to 'see'?"
"You would too, if you lurked around a bit more, observed harder and gossiped a little with the other nerves."
"Alright. Let's do it!"
"One conjured visual information coming up!" and they laughed.
Hearing Things That Are Not There
"It's extremely still, do you not think?" the Right Auditory Nerve said. "I wish there are some to encode and deliver. Music will be nice."
"Depends on the kind of music, you know," the Left Auditory Nerve replied. "I don't want those loud, booming ones. They're so obnoxious they make me feel like killing myself."
"Yes, killing myself. Ha ha."
"Hey, I could help you with that. What do you call it? That's right, MERCY KILLING! I'll kill you! Ha ha ha..."
"Ha ha ha..."
"What?" the Left Auditory Nerve was taken aback by the Right Auditory Nerve's sudden solemness.
"My last message to you, I accidentally sent to the Brain as well. Now it's thinking someone is talking to it."
"We can do that?!"
"Cool! Let's try again!" and they laughed.
I can't decide. I'll need to have a serious talk with those naughty, misbehaving nerves.