A few years ago, I interviewed Nicola Roberts, the best member of Girls Aloud, to talk about her underrated debut solo album Cinderella’s Eyes. She discussed what it was like to be on Popstars: The Rivals, the TV singing competition that predated The X Factor and gave birth to the band. What stood out most to me was how it felt for her to ricochet between two worlds. She was 16 and split her time between TV studios in London, and hanging out at the chippie in her home town of Runcorn. She remembered being taken to a fancy dinner at an expensive restaurant where none of the girls could understand the menu. She had to ask the head of Universal Records: “What the fuck’s coriander?”

It doesn’t take much to get me on to Girls Aloud, but I thought of that particular anecdote when I saw the State of the Nation report by the Social Mobility Commission this week. Its findings are a sobering confirmation of what is apparent to anyone whose world is not centred on London or the slim area surrounding it. Social divisions are deeply entrenched in British society, and social mobility, this notion that you can be born “disadvantaged” and step outside of such circumstances given the right opportunities, increasingly looks about as achievable as the UK’s chances of walking away from the EU without self-destructing in the process. Alienation and resentment are growing, and for rural, coastal and formerly industrial areas in particular, the outlook is grim.

In some ways, the urgency of the report and its insistence on a “new level of effort”, its assertion that “tinkering around the edges will not do the trick”, should be a cause for optimism, if not a clear call to action. But it left me feeling certain of the idea that Britain’s relationship with class is as rigid and immovable as it ever was. I have some experience of what social mobility feels like, and it’s a complicated road to travel, filled with “what the fuck’s coriander?” moments and a constant sense of performance anxiety: as with wealth, opportunities and privilege are almost entirely hereditary, and passed on from one generation to the next. To come to them suddenly means that you are expected to learn a new set of rules and a new way of being, and the pressure of fitting in to that can be exhausting.

I was born into a working-class family in north Lincolnshire, an area of the UK that, according to the Social Mobility Commission’s map, is a concentration of what it calls “cold spots”. The report ranks 324 local authorities in order of their chances of social mobility; where I grew up, the areas range from 165th on the list to 309th (17 of the top 20 are in London). I was the first in my family to get A-levels, and then the first to go to university. A scheme set up with the explicit aim of improving social mobility directly changed the course of my life: the Sutton Trust paid for me to attend a summer school in Oxford to get some experience of what university life was like. In that sense, it actively replicated hereditary privilege and stood in for what might have been passed down to me by relatives, say, if university had been a family tradition.

Largely as a result of this scheme, I went to university, to Oxford, where I learned that one of the key markers of the class divide is confidence – if you’re born into an advantaged background, confidence practically comes home with you from the hospital; otherwise, you have to learn it as carefully as you would a musical instrument. As a result of that education, my life is now middle class by most standards, though if you’ve been socially mobile, the question of identity is perpetually tricky: are you the class in which you were born, or the one you’ve become?

Moving around makes you a permanent outsider, even if you’ve learned the rules. Nothing quite fits right. You’ll see again and again that the class system is not built for people to question, or bend. From the food you know to the accent you have to the holidays you’re familiar with, it’s all different, whether barely perceptible or glaringly obvious. I remember having to teach people at university that gravy went on chips. You are constantly reading the menu and asking, what the fuck’s coriander?

When Theresa May became prime minister in 2016, her speech promised to usher in a new age of social mobility, and a levelling of the playing field. “When it comes to opportunity, we won’t entrench the advantages of the fortunate few. We will do everything we can to help anybody, whatever your background, to go as far as your talents will take you,” she said. But letting the odd person pull themselves up by their “talents” – bootstraps, by any other name – is not only insufficient and inadequate, it’s insulting to those who, for whatever reason, simply don’t have access to the opportunities. Instead, her government’s austerity-driven policies may have slammed the door closed for generations. The Social Mobility Commission’s latest report should serve as a rude awakening. Privilege deepens like a coastal shelf, and a fantasy of meritocracy, always just out of reach, isn’t nearly enough to paper over the cracks.