The Overwhelming Power of “Can’t”

Buying what your thoughts are selling can create self-fulfilling prophecies

Photo by Sigurdur Fjalar Jonsson on Unsplash

What an impossibly glorious day it was in Pembrokeshire, South Wales. Seagulls called and swooped against the backdrop of blue skies, the green pastures were dotted with dark-grey stones and edged by a ribbon of well-worn coastal path, and the waves broke dramatically at the foot of the sea cliffs.

I didn’t give a toss about any of that.

In fact, I was hurling silent curses at every single element of this stunning scenery.

Why should I admire the seagulls when they were swooping at my head? Should I give a damn about a coastal path I was pretty sure I’d never see again, or thrill to the sound of waves against rock when all this meant was that the freakin’ tide had come in?

I hated the sea cliff the most, because my quivering, sweating body was pressed up against it for dear life. I was wearing a stupid harness, tethered by a stupid rope, having been talked into this stupid endeavour by a stupid man. Only about halfway through the route, unable to go either up or down, I was entirely stuck.

Everything sucked. You are never going to get out of this, hissed my mind. You are going to die. Die, do you hear me?

‘Get up on your toes and find a hand hold over on the right!’

This more helpful suggestion reached me only faintly, challenged by the sound of waves and wind, and it emanated from the Stupid Man far above me. For someone who was about to be responsible for my untimely death, he sounded pretty chilled, and I suspected that he might even be enjoying a nice cup of tea warmed up on the portable stove.

I mustered all my strength, drew sea air into my gasping, panic-beset lungs, girded up my courage. I did my best.

‘I f***ing hate you!’ I screeched, throwing my head back to make sure he heard. Then I pressed my cheek back against my own little bit of inhospitable volcanic rock, a 20-cm-square patch I’d come to know intimately over the past half an hour.

You might have guessed this already, but I’m not much of a climber.


You hear a lot about the power of self-talk, about how your mind likes to brand your every worst-case scenario with the 100%-guaranteed stamp of Truth. Your mind is a persuasive, emotive, masterful storyteller, the eye-spinning hypnotic Kaa to your drooling Mowgli. (Trust in meeee…just in meee…) The stimulus/response relationship we have with our own internal stimuli — the thoughts, feelings and images our brains produce — is often automatic and seamless.

We might throw around the phrase ‘internal dialogue’, but much of the time we don’t experience it as a dialogue at all — your mind says jump, and you jump. Your mind casts out a line, and you bite the hook and are reeled in again and again, like a big dumb fish in a catch-and-release lake, unable to resist the lure long enough to check if it might be a trap.

Your gullibility is understandable. All sorts of societal messages reinforce our tendency to believe what our minds tell us. ‘Trust your gut,’ you’re told, so if you have a thought that gives you a feeling in your gut, you pay attention. You wouldn’t steer yourself wrong, right? You should follow your instinct, shouldn’t you? Well, that depends.

Your mind thinks it’s got your back — it’s only looking out for your safety and, mindful of protecting you from harm, it’s often inordinately cautious. That’s its evolutionary remit.

Be careful! Don’t try that! Something bad will happen! You‘ll get hurt! You’ll get killed!

For nearly every anxious or depressing thought your mind sends you, if you look hard enough, you can spot the protective intent behind it. Lovely, cheers for that, mind, but it might not actually be in your best interests to go along with everything it says. The brain actually has a tendency towards ‘destructive normality,’ as Russ Harris describes:

[T]he psychological processes of a normal human mind are often destructive, and create psychological suffering for us all, sooner or later. Furthermore….the root of this suffering is human language itself.

Psychotherapeutic practitioners have various approaches in working with people who suffer from anxiety and depression. Those who practice from an Acceptance and Commitment Therapy (ACT) perspective encourage clients to develop their capacity to just notice what their mind is giving them, from what I call a kind of observation platform perspective.

This is sometimes called ‘defusion’, and it’s a skill that helps us to be far more flexible in the face of all sorts of thoughts, feelings and circumstances.

I’ve taught defusion to a lot of people. But for me, this moment on the sea cliff — okay, this hour and a half on the sea cliff — was the occasion on which I came to thoroughly, personally understand the power of self-talk, and the consequences of fusion with my beliefs, in an acutely embodied way.

Stuck in one spot, halfway up the rock, there was a playlist of short, emphatic, declarative sentences on loop in my brain.

I can’t.

I can’t do it.

It’s impossible.

I can’t.

I was as tightly fused with those thoughts as my fingers were fused with the lumps of volcanic rock I clung to. And as long as that was the case, it was literally impossible to move. As long as I believed in these thoughts with absolute certainty, I was unable to mobilise a single muscle in my fingers, arms or legs. My entire body ached with maintaining the stillness, my physical rigidity mirroring the rigid and inflexible quality of those sentences.


I don’t know what happened to trigger it, but about 45 minutes into this ordeal, something happened. A small channel opened, a connection to my professional experience, a dim awareness that I wasn’t practicing what I preached. A little edge of observational capacity peeled away from the stuckness, and a wormhole opened into a different vantage point.

Instead of being fused with my thoughts, I suddenly noticed what I was thinking. I became the noticer of my own experience, of the content of my mind.

When I became the noticer of my thoughts rather than just the thinker, the horizon of possibility suddenly opened. My mind flashed back to an old story, The Little Engine that Could, a classic American book and a childhood favourite of mine. A little blue engine is prevailed upon to help a beleaguered train to get over a mountainside. Petite and delicate-looking, the Little Blue Engine appeared as ill equipped to perform this feat as I was to climb this cliff face, but the engine decides to give it a try anyway.

At first it all looks doubtful, but with a lot of huffing and puffing, and a continuous mantra of ‘I think I can, I think I can, I think I can,’ the Little Blue Engine reaches the summit and races the cargo down the other side into the valley, triumphantly repeating, ‘I thought I could, I thought I could!’

A moment earlier, there had been no way my mind would have had the bandwidth to access a memory of The Little Engine that Could. This was another sign that defusion was happening.

Then a phrase popped into the space created in my mind, the distance that was growing between my observing self and the ‘you can’t do this’ thought. ‘Those who can’t do, teach,’ it went. Bloody hell, thought the newly-freed-up, values-aligned Me. I’m don’t want to be someone that tells other people to do what she can’t or won’t do herself.

The fingers of my right hand twitched. I drew another breath, went up on my toes as the not-so-stupid man had suggested, loosened my death grip on the lump of rock and reached for the next hold.


About seven minutes later, as incredible as it seems, I was sitting on the coastal path, looking out over the sea, profound relief and gratitude washing over me.

‘Doesn’t it feel good to have done that?’ inquired the stupid man.

Not quite ready to be as grateful as all that, I levelled him with the gaze of death.

No. I didn’t feel good to have made that climb. I didn’t feel good about having conquered the cliff. I hated that cliff and I hated climbing, and I pretty much never did it again. It’s not my idea of fun, and that’s okay.

But I did feel good about one thing. I had conquered my own thoughts, my own mind. And my ability to do so started simply, with noticing my fusion, the first step on the road to defusion.

(Want some defusion exercises and metaphors that you can employ yourself? Here you go.)

I don’t experience cliff-hangers like this every day, and I hope you don’t either, because that much sustained adrenaline isn’t very good for you. But every day, in all sorts of situations, you have the opportunity to observe your own thoughts, to de-fuse, to climb onto the observation platform.

It sounds simple and often isn’t, because of the Svengali-like power of your mind, which so likes to scream ‘You can’t!!!’ when you encounter what it believes to be danger. But with practice, it becomes easier and easier. When you can click readily into being the meta-level noticer of your thoughts, rather than the fused, gullible thinker, life gets a lot easier.

That’s the kind of ability that allows you to consciously, mindfully opt out of fulfilling your own mind’s prophecies. Moments of noticing what your own mind is giving you are the moments when you can start to open up, be more flexible, and do what matters to you.

And when you make that happen, you can get to the top of your own cliffs, whatever they may be.