Gut First, Excuse Later: How Your Brain Writes Stories to Justify Your Instincts

In a near-silent lab, with only the ticking of a clock and the mouth-breathing of a furrow-browed doctor in a crumpled white coat, the patient sat in the warm buzz of mild sedation. 

The researcher showed him two images—one to each eye. 

One image entered his right eye, connected to the left hemisphere of the brain, where language is stitched together. It was a chicken claw. 

The other image hit his left eye, sending information to the right hemisphere—home of intuition, pattern, and spatial awareness. It showed a snowy scene. 

“Point to the related object,” said the researcher. 

The man didn’t hesitate. His left hand pointed to a (fake) chicken. His right hand chose a snow shovel. 

So far, so interesting. 

But when asked why he chose the shovel, things got weirder. 

Now he had to respond in language. So the left side of the brain—the linguistic side—took over. And while it knew about the chicken, it had no access to what the right hemisphere had seen or decided. After a rare but fascinating operation, the two halves of his brain could no longer talk to each other. 

The right hemisphere, which had picked the shovel, had no language to explain itself. It couldn’t say why. It couldn’t even say what—it didn’t know the word “chicken.” But the left brain, still holding the mic, didn’t panic. It did what it always does: 

It made something up. 

“Well,” said the man, with the calm confidence of someone describing how toast works, 

“chickens live in a chicken coop. And they need shoveling out, don’t they?” 

He made up a story to dispel the confusion. 

The operation is called a corpus callosotomy. It involves severing the connection—the corpus callosum—between the two sides of the brain. It’s sometimes used to treat severe epilepsy and often works. But it reveals something startling: when the brain is split, each half can function independently. And the half with language will confidently explain things it doesn’t understand—because it has no idea it doesn’t understand them. 

This isn’t just a strange lab trick. It tells us something important: 

we can’t always explain why we do what we do. 

And more often than not, we’re completely fine just making it up. 

You’ve probably heard people talk about being “left-brained” or “right-brained,” usually as a tidy explanation for why someone’s bad at math's or likes abstract painting. 

This is warmed-up garbage. 

Yes, you might lean toward numbers, music, logic, or dreams—but in healthy adults, both hemispheres are online and constantly collaborating. You are not half a person. You are two distinct processors trying to run a shared life. 

Even birds have this split. Ian McGilchrist, in his astonishing book The Master and His Emissary, describes how a bird feeding on the ground uses one eye to search for food—and the other to scan the sky for predators. One half is focused. The other is watchful. 

Your brain is the same. 

You need to focus. 

You need to stay open. 

Both sides are always working. 

They just don’t always agree on what matters most. 

Maybe you’ve heard that whisper: “Go.” 

You’re offered a job. It means leaving people you love. It’s bad timing. Julia’s operation. Ned’s swimming lessons. The dishwasher just broke. 

Still - “Go,” says the voice. Quiet. Certain. 

And even though the logic doesn’t stack up, you take the job. Or marry the sweetheart. Or quit the team. Or go to the pub. Then, later, you explain it. 

You talk about pensions. Opportunities. Risks. Alignment with your goals. All very sensible. 

But let’s be honest: you didn’t do it for the pension. 

You’d already left. 

Your words just followed. 

We’re taught to be rational. We’re expected to explain everything. To make decisions that make sense to others. To pass the test of reason. But most of the time, the hard part isn’t deciding—it’s creating a story that sounds like we did it “properly.” 

The two sides of your brain are each applying different rules, focusing on different worlds, using different metrics for truth. 

They both think they’re in charge. 

And if you don’t learn how to let them talk—really talk—one of them will always win. Usually, it’s the one that speaks the loudest. The one with language. The one with reasons. 

That’s the one the modern world prefers. 

It’s also the one that might just be patching meaning onto something older, deeper, and far less polite. 

You don’t need to have your brain split in surgery to miss the deeper reasons for your choices. 

So next time your gut whispers, and your logic scrambles to catch up—ask yourself: 

Am I looking at a snow shovel and talking about chickens? 

You can find out more in my forthcoming book “Meaning and Mayhem: Getting to Know Yourself in a Chaotic World”