"From what you've described to me, it sounds like your brain is undergoing rapid shifts in chirality." The doctor's eyes were focused on his tablet. “Like you’re suddenly trading places with the other side of the mirror, yes?“
“Yeah, that’s one way to put it. But what could cause something like that?"
“Well, the exact cause is unknown, but our current model suggests that when this happens, each hemisphere of your brain is operating under the assumption that it is your entire brain. Whether or not that's true, we can treat it by using this operating assumption. I'm writing you a prescription of enantiodromine, which should prevent these sudden reversals by slowing the synaptic traffic across your corpus callosum. As long as you take your dose regularly, left should remain left, and right should remain right."
“I’m willing to try it, but this whole thing has me wondering about something. Mind if I run something by you?“
His patient gazed at the floor for a minute, collecting his thoughts. "I've been thinking about how left and right are relative, and how when these shifts happen for me, they don't seem to happen for anyone else. How left and right are relative directions, unlike the compass ones. That's all well and good for me. But then I get to thinking about mirrors. If I'm looking in the same mirror as someone else, we'll both see the same flip in chirality, right? That’s something objective?”
"So then, I got to thinking, what would happen if someone, I don't know, maybe God, had a mirror big enough to surround the entire universe at once. Let's ignore the physics of it for a moment, and just roll with that idea. Wouldn't that mirror image necessarily show left and right reversed everywhere in the cosmos, for everyone gazing into it?"
"What are you suggesting?"
"That if you can reverse left and right universally, regardless of the perspective of any individual observer, then there must be some form of objective True Left or Right, just like there is a True North.”
"Hmm. Perhaps you mean clockwise, or counterclockwise? Those would seem to fit the bill of what you're describing."
"Not exactly, doc. Which half of my brain is the clockwise half?"
“Ah, fair enough. Well, that’s an interesting idea, I'll give you that. I’m not sure what a Universal Left or Right would mean, but I’d be inclined to believe that they exist if you could point me in their direction."