Reading about the decision by the Crown Prosecution Service to prosecute a 10-year-old child for using the word “Paki” last week, got me thinking about the paranoia and confusion around the issue of race nowadays. When I was called a Paki at school, it was often by black kids who I’d cuss back at with racist barbs of my own. It was part of the ignorant ruck-and-maul of growing up working-class in multi-ethnic west London. But the strange logics that surround race aren’t confined to the rough children of the lower orders.

My friend Diane, a black single mother, lives next door to a lovely middle-class white family. She told me an interesting story. The neighbour had ticked off her adolescent son for using street slang rather than correct English; the boy then accused his mum of racism for disliking “black” argot. Given that Diane is scrupulous in ensuring her own son is well spoken and articulate, this provided food for thought. It shows how well-meaning white people, even the young, can have extremely misplaced ideas.

The 14-year-old boy next door is a sweet kid, but had assumed that trash-talk is the way black people speak and is a valid language in its own right. Diane doesn’t even let her six-year-old son watch MTV in case he imbibes retarded notions about how he should behave from rap videos made by multinational white-bread corporations.

Gangsta rap makes millions by pandering to a middle-class fetish. It doesn’t make money out of kids in the ’hood; they buy their music bootlegged or copy it from friends. But white suburbanites donate a fortune to crotch-grabbing dummies who prance around “keeping it real” for their delectation.

Diane is rightly disgusted by the misogyny and homophobia that often make up the lyrics. She has high hopes for her children, and doesn’t want them ruined by the music industry myth that the epitome of blackness is to be a scumbag who brags of abusing black women and killing black men.

White people murder and peddle drugs, too, but those themes don’t dominate the music white people make. Gangsta rap and its British equivalent, grime, take one sordid fact of human life and explode it out of all proportion, so it appears to be definitive. But the naive white kids who buy into it would never consider themselves to be racist. They see themselves as right-on hipsters who sympathise with the black experience.

Groovy white liberals can pose serious problems to ethnic minorities in this country. They contributed to some of the most enjoyable and least productive moments of my childhood. I went to an all-boys comprehensive school in Ealing; the pupils were overwhelmingly black and Asian. Some, like me, were the children of Indian immigrants, others, refugees from Somalia, Iran, Armenia . . .

We’d often get a fresh-faced, idealistic teacher who had no doubt read Marx and Malcolm X and done an elective in post-colonial theory at polytechnic. We ate those suckers alive.

Desperate to empathise with our persecution, they were knocked dead by our indifference and rampant misbehaviour. At the first sniff of guilt-ridden middle-class weakness, the feral instincts of teenage boys were unleashed and the class descended into anarchy. They thought we’d been crazed by oppression, so didn’t want to come down too hard on us. They wanted to understand instead. When it did get too much for them and they threatened to march one of us to the headmaster’s office, our immediate protest would be: “You’re a racist!”

They’d cower behind their desks, mortified that we’d recognised some deeply suppressed prejudice within them, while we got back to hurling insults, beating the crap out of each other and rolling joints to smoke at lunchtime.

The softest touches were always female. For many women, empathy and “emotional literacy” (whatever the hell that is) are a greater priority in the workplace than actually doing the job they’re paid to do. We had a whale of a time whenever a liberal white female was in charge.

A stalwart gang of diehard traditionalists prevented us from leaving school illiterate. Chief among them was Mr Garrett, my form tutor. He was an imposing behemoth of a man, who couldn’t have cared less about our ethnicity and historical subjugation. He had high expectations of how we should behave and apply ourselves, and flew into thunderous, terrifying rages whenever we failed to meet them.

He was the kind of guy who’d never get a job in education today. For some kids he was the most solid male presence they had in their lives. Whenever I bump into former classmates in my old neighbourhood, he’s the teacher we remember most fondly, wondering how he’s doing now. He didn’t always have our affection, but he commanded our respect. He saw enough innate worth in us to set us standards and be bitterly disappointed when we fell short.

Things are very different today. I have a friend who teaches, and he says it’s normal for teachers not to reprimand badly behaved black kids because “they suffer enough oppression as it is”. The soft bigotry of wet liberals is as insidious as the racism of white supremacists. Lowering the bar for children because you consider them oppressed has the same effect as expecting little of them because you think them inferior.

We could never pull our stunts on Mr Garrett. He was hard on us all — black, white and brown — but rigorously fair. I can still remember his face, purple with anger, as he folded and refolded a piece of paper, straining to control his temper after I’d been reported to him for a misdemeanour. He was the only teacher who ever inspired shame in me.

It’s 16 years since I left his care, and I’m now a writer who has just had his first novel published. If Mr Garrett is reading this, I’d like to thank him for myself and on behalf of all the other boys whose lives he impacted so furiously, and so positively upon.

Tourism, by Nirpal Singh Dhaliwal, is published by Vintage, £7.99