I am often extremely dismissive of people immersed in their smartphones. I tut at the mole-ish pedestrians who step out into the traffic, faces uplit and shocked when a car goes by. Last week, in a toddler playgroup, I actually hissed at some poor father. We were in the middle of ‘The Grand Old Duke of York’, with actions, when he got stuck in an iPhone trance. There he stood amid the marching midgets swiping from text messages to email to Twitter and back again. It was when he tapped on the bus times app that I snapped. Well, what a hypocrite I am. And how is it that I’ve only just noticed?

I was on my bike, in sight of Spitalfields Market, when I realised what I’d become. I tell myself that it’s important I check my mail; that it’s grand the way a smartphone lets a mother work even as she’s grilling fish fingers. But here I was, getting my phone out at each set of traffic lights, checking email and Instagram. It was dark, spitting rain and bitterly cold; hard to pull the handset from my pocket and near impossible to dry the touchscreen enough to use it. Still, whenever the lights were red, my right hand reached for it with the sort of practised fumble a drunk reaches for a ring pull. Am I a phone addict? I asked my husband when I got home. Yes, he said.

This story’s been written many times. I’ve commissioned pieces on the dangers of smartphones; I’m well aware that the men who made millions from phone tech now bring their own children up screen-free. Even so, I’ve never before paused to consider my own habit, and it’s genuinely disturbing.

We hear a lot about the terrible content of the internet and how damaging all the porn and bikini bodies are to teenage self-esteem. I don’t know a soul who doesn’t emerge from a dip into Facebook or Mail Online feeling grubbier. But as I watch myself I realise it’s not any particular content I’m addicted to. The dopamine hit comes from the sense of getting something new.

No new emails? I move to Instagram, then on through the caravan of apps. I’m like a monkey pushing a button for peanuts. And there’s always a peanut somewhere. Perhaps my Uber rating has changed, or the weather in some place I once went on holiday.

And slowly, incrementally, the real world fades away.

Does that matter? Some say not. I was once told by a man who had written a seminal book about the internet that the non-virtual world, ‘meat-space’, is overrated. The world online is a better one, he said. We have more choice, we can collaborate more, be better friends, more ethical shoppers. But what if I’m not using the phone to access the world so much as using the world as an excuse to use the phone?

I enjoy cooking, but these days I also think: what fun to google recipes for a bit, to flop backwards onto the sofa, adopt the iPhone otter pose. What fun Christmas is. How nice to think of others. But how pleasant also to have an excuse to lie around browsing Amazon, with the double dopamine satisfaction of clicking ‘buy’. ‘Not now darling,’ I’ve told my son, while I’m scrolling through photos of him, looking for the perfect home screen to show the world how much I care.

Like all clever jailors, Apple tries to befriend us, to persuade its prisoners it knows the way out. Why not monitor your screen time? suggests my phone. Why not set a time limit on certain sites?

Because that’s useless, as Apple knows it is. It’s novelty that’s addictive, new notifications and messages, so time limits are a red herring. There are just too many apps, too many excuses to surf the net, and for an average Joe with no self-control, every surf session ends up with you lost in the undertow.

Perhaps you begin by googling that pain in your neck to set your mind at rest and save the GP time. An hour later you’re in a chatroom for spine cancer survivors wondering if you’ve made a will. I’ve stood over my feverish son, googling the symptoms of sepsis, and actually persuaded myself I can see them. Look, he’s limp and blotchy, he’s fitting. Let’s go to A&E. Put the phone down, and look again, says my husband. He’s fine.

How I used to laugh at my teenage nieces for multi-screening: watching films on wide-screen with a smartphone in their hands. No wonder your generation are depressed, I’d say. Go outside, climb a tree.

Look at me now. Sunday nights I spend sitting on the sofa watching The Little Drummer Girl on TV while googling Alexander Skarsgard on the phone. After episode one I could have won a quiz on the subject of his early life. By the finale I’ll be rivalling his mother (My Skarsgard, 62). As for the plot of The Little Drummer Girl — not a clue.

On Saturday morning, I bought a Nokia handset. I did it in an impulsive fit of self-loathing, in the same way I once used to throw away full packets of Marlboro Lights. With the last remaining fragments of my concentration, I extracted the iPhone SIM card and put it into the new, old phone — no internet connection, no apps, just old–fashioned texts. Some pressure I hadn’t known was there lifted. I felt instantly, pitifully free.