Like so many of France's mega-estates, this one was mind-numbingly ugly, a forest of Sixties social housing blocks on the outskirts of a large post-industrial town. My friends and I all knew to avoid the local cite, as the French call these tragic enclaves.
I was a schoolboy at the time in Mulhouse in north-eastern France, where I was born: merely using the lone bus route that went through the estate was deemed too risky. We would have made easy prey for the gangs, and we all remembered the day that the bus was shot at.
Eventually, the authorities decided that it was too risky for ticket inspectors to do their job, even on the other, much nicer bus routes we used to go to school: they would only ever turn up accompanied by 20 heavily armed, riot-ready policemen, poised to drag out troublemakers.
As for this cite and others like it, it was clear that the authorities had little interest in their residents, known as banlieusards. The police would come out en masse if they were called, albeit reluctantly; they knew that they would be met by groups of angry youths resentful that they had entered what they saw as their fiefdom. Every New Year, cars would be torched: violence and law-breaking was normalised.
The cites were in France, but it was almost as if they weren't really controlled by the French state. Some residents, who were predominantly first or second generation immigrants, usually from north or sub-Saharan Africa, managed to get on and move out, against all the odds and despite widespread, barely concealed discrimination; many couldn't or wouldn't, stuck in permanent joblessness or dragged into drug-dealing. The local gangs and their supporters hated outsiders and the forces of law and order; the wider public despised all the banlieusards and wished they didn't exist. It was sad beyond words, a ticking time-bomb beneath French society.
Just a short drive away from those hopeless, graffiti-ridden estates in Mulhouse lie Alsace's picturesque villages and the Rhine valley's beautiful vineyards, visited by thousands of middle-class British tourists every year who, needless to say, are oblivious to France's other side.
The unfairness is staggering, especially in a Left-wing country obsessed with social justice and redistribution; in my day our Marxist teachers would lecture us endlessly about what they imagined were the inequities of American and British capitalism, blind to the home-grown failures of French dirigisme just around the corner.
Tragically, virtually no progress has been made tackling the crisis in France's housing estates since I finished school and moved to Britain 20 years ago. Much has changed in France overall, but all of my observations remain true, apart from the fact that there is now another route into the estate and a handful of buildings have been demolished. For those of us who love France, this is heartbreaking. The plight of the suburbs, or banlieues, and those who live in them, is not just deeply immoral: their continuing isolation poses a major national security threat. Islamist extremists have found it all too easy to recruit in the cites, filling some of the void left by the collapse of other forms of authority and the state's wilful neglect.
Last week's terrorist horror reminds us yet again of an unpalatable reality: it's not just that unemployment, crime and family breakdown in the banlieues remain as bad as ever, in itself an unforgivable cross-party failure, but one element has actually got worse: fanaticism is on the rise. Those who speak and engage with young, alienated banlieusards have been shocked by the gradual change in tone over the years, by the radicalisation, the casual anti-semitism, the conspiracy theories and many other dangerous signs. Economic grievances have mutated in a catastrophic manner; given the rhetoric, it is hardly surprising that many of the deluded French extremists who have travelled to Syria to fight for Isil come from the banlieues.
Manuel Valls, France's surprisingly good prime minister, is one of those who sees this. Mugged by reality, he is calling for a law and order crackdown. But his party clings to its previous views on economic, education and social policy, which makes progress impossible. Some 7 per cent of the population is crammed into 751 "zones urbaines sensibles", the official name for the sink suburbs. Only 20 per cent of their 4.4 million inhabitants own their homes, with the vast majority social tenants. The idea that the problem is a lack of public spending has been tested to destruction since the riots of 2005.
The real problem is the ongoing, multi-decade failure of French public policy in almost all areas.
The red tape and taxes that prevent entrepreneurs from creating businesses and new jobs affect immigrants disproportionately. One shocking study revealed that in 2011, 23 per cent of Algerian immigrants and 25 per cent of Turkish ones were out of work, against 8.5 per cent for non-migrants, a far greater gap than any equivalent here in Britain. The situation is even worse for members of such groups trapped in sink suburbs.
On top of the disincentive to create jobs, France's welfare state is unreformed: there has been no effort to tackle the sorts of welfare traps that the US and the UK have both focused on. The post-1968 revolution in education has slowly hollowed out France's once-famed schools. In the US and UK, the authorities fought back against crime, instituting zero-tolerance policing; France remains soft on criminals and tolerates too much social disorder. That too must change.
Most depressingly of all, France's defining post-revolutionary philosophy may be incompatible with the modern world. It is monolithic: there can only be one national identity, one national educational system, one version of Frenchness. Yet that doesn't work: in a liberal society made up of multiple communities, something needs to give. Britain's approach, while also flawed in some ways, is working better: the visit of Prime Minister Modi last week highlighted our flourishing community of British-Indians, for example. France too needs to learn to love the idea of multiple, hyphenated identities, which remains anathema to its ruling class. Its immigrants must become French, learn the language and embrace its laws, but must be allowed to retain a separate, subsidiary identity. It's integration, not assimilation. At the moment in the banlieues, though, France is getting neither.