Why Thoughts Feel So Real (and Why Knowing That Still Isn’t Enough)

If logic hasn’t helped you manage overthinking, you’re not broken. Your mind is doing exactly what it evolved to do.

In our last session, we talked about why arguing with your thoughts tends to make them louder. Today, I want to slow things down and look at something more fundamental: why thoughts feel so real in the first place—and why insight alone is often not enough to change how we feel.

This is where many thoughtful, intelligent people get stuck. They understand the psychology of overthinking. They can explain their patterns perfectly. And yet… the mind still feels hijacked.

So what’s going on?

The Science: Why Thoughts Feel Real, Not Just "Mental"

It is a very common human experience to feel that even when we know a thought is irrational, it still feels deeply true.

Your mind doesn’t experience thoughts as abstract data. It experiences them as events.

When a thought shows up—“I’m failing,” “Something’s wrong with me,” “This feeling means danger”—it doesn’t arrive labelled “mental activity”. It arrives as meaning, urgency, and often threat.

That’s because the human brain evolved to prioritise survival over accuracy. It’s far more concerned with keeping you safe than with being right.

So when your mind links a thought to danger, loss, rejection, or failure, it reacts as if something real is happening. This is the core reason why thoughts feel real—your nervous system doesn’t wait to debate the validity of the threat. It just responds.

Why Logic Won't Stop Overthinking

Many people assume that once they understand why they think the way they do, the anxiety should settle. And insight does help—just not in the way most people expect.

Insight works at the level of content:

• “This belief came from my childhood.”

• “I know where this pattern started.”

• “I can see the logic error here.”

But intrusive thoughts don’t persist because the content is wrong. They persist because of how tightly the mind is holding onto them.

You can know a thought isn’t helpful and still feel impacted by it. In Acceptance and Commitment Therapy, we don't call this failure. We call it Cognitive Fusion.

Understanding Cognitive Fusion (The Sunglasses Effect)

To understand Cognitive Fusion, imagine you are wearing a pair of dark red sunglasses. You’ve had them on for so long, you’ve forgotten you’re wearing them.

When you look at a white wall, you don’t say, “I am seeing the wall through red lenses.” You simply say: “The wall is red.”

This is exactly what happens in the mind. When we are fused with a thought, we don't see the thought; we see the world through the thought.

• Fusion: "My life is a mess." (The wall is red).

• Defusion: "I am having the thought that my life is a mess." (I am looking at the red glasses).

This is why you can't "logic" your way out. Logic is just describing the red wall in more detail. A sense of ease often comes not from fixing the wall, but from taking the glasses off.

The Shift: Changing Your Relationship to Thinking

Here’s the part that often surprises people.

Navigating overthinking rarely comes from getting better thoughts. It usually comes from developing a different relationship to thinking itself.

Instead of asking: “Is this thought true?”

The more useful question becomes: “What happens to my life when I treat this thought as truth?”

And even more importantly: “Can I notice this thought without stepping inside it?”

This isn’t about suppressing thoughts or forcing calm. It’s about learning how to step back just enough that thoughts can be present without running the show.

A Micro-Move for This Week

We are going to go deeper into how to practice this in our next post, but for this week, I want you to try one tiny shift to interrupt the Cognitive Fusion loop.

When a familiar, heavy thought loops in your mind, try to Identify the Genre.

Instead of arguing with it, simply say to yourself:

• "Ah, here is the 'I'm Not Good Enough' story again."

• "Radio Doom & Gloom is broadcasting."

• "The Worry Playlist is on shuffle."

Don't fix it. Just name it. See if that tiny label creates a millimetre of space between you and the noise.

Next time, In Session with Brett:

We’ll talk about how to recognise when you’re fused without analysing it, what defusion actually looks like in real moments (beyond just labelling), and how to practise this shift gently.

Because the goal isn’t to stop thinking. It’s to stop letting thoughts decide who you are.

Stuck in the loop right now? If you are looking for support to understand and manage these patterns, our team works with anxiety using approaches such as ACT.

Book a session or meet our team.