Was it seeing the little girl in the supermarket queue tugging her father’s sleeve for attention as he texted that did it? The way that, after a few minutes of being ignored, a look of abject fear crept across her face. “Daddy,” she whispered, “can you SEE me?!”

Or was it the knowledge that I felt relief rather than inner horror when people checked their phones during lunch, because it meant I could do the same, that started me on a long-overdue digital detox?

In fact, it was the realisation that I couldn’t read any more that did it. I had, unusually, a whole afternoon to myself and settled down with a book. Except I couldn’t settle. I calculated later that I went no more than seven minutes without having to check email, Twitter, Instagram, WhatsApp or a shopping website on my phone.

And I did have to. I itched somewhere inside if I didn’t. That’s what addiction feels like, of course. But what was I supposed to do? NOT keep an eye on friends (and their new shoes, their dinners, their cats and their…)? Go without notifications of what could one day be a life-changing email? Fall behind on my grasp of the latest sub tweets? Please.

Then I came across a book by Natasha Schüll, Addiction By Design, and had the epiphany I needed. It talks about how smartphone systems and software hook us in. Features such as automatic notifications, autoplay and scrolling basically work on fruit machine principles to keep us engaged. To deliver the little dopamine hits created by novelty – no matter how trivial or ultimately disappointing the content – and get us craving more.

“My name is Lucy and I’m a phone addict”