After the baby boomers, the flower children and Thatcher’s babies, who were we exactly – Major’s lotus-eaters? Will history bother to name a generation that fought not for freedom, nor for peace, nor love, nor money, but who maimed themselves through their consumption of drugs?

“All you have is your honesty,” a teacher once said to me. I had been thrown out of my old school for smoking dope and was now trying to get into his.

This week honesty and dope had a rare rendezvous. Two cheers then for Jacqui Smith, the home secretary, and two for Tony McNulty, responsible for the police. Two cheers for Alistair Darling, Ruth Kelly and Hazel Blears. They have smoked dope (no surprise, they’re normal people), they have admitted it (some surprise, they’re politicians) and they have learnt their lesson. But what lesson would that be?

We will not know until next year when the UK’s 10-year drugs strategy is renewed. We will not know until the prime minister decides where he stands on his nation’s use of cannabis (we know he believes his ministers’ use is “a private matter”). We may not know for five years, when we will be able to trace the trends. We had better hold that third cheer in check.

Smith says she tried it “just a few times”, Darling “occasionally”. Andy Burnham, chief secretary to the Treasury, and Blears say they smoked it “once or twice”. I believe them. If they had seriously got into it – like I did – they would not wield such power.

One of the few barely spoken triumphs of the Labour decade is that since 2000 cannabis use first levelled off, then began to fall. The UK Drugs Policy Commission, which reported in April, has no idea why. Throughout the 1990s, across the western world, cannabis use rocketed, up by half from 1992 to 1998. From Finland to New Zealand we all smoked like hell. And neither education, nor intervention, prohibition, testing, relaxation – in fact nothing seemed to make the slightest difference. In Australia they relaxed laws, while the Americans tightened theirs. No matter: half a generation, my half of my generation, just kept on getting high.

“Cultural factors”, the commission notes, were in control. With drugs they always are.

My generation came of age in the 1990s. The Berlin Wall had fallen, Nelson Mandela was free, peace was even sidling into Northern Ireland.

If you are in your late thirties or forties with a family, perhaps I am your tricky, unmarried youngest cousin. If you are a child, I might be your funny uncle, the one who makes your parents laugh, before they shake their heads. If you are in your twenties I am probably, as one of you said to me: “The last generation who thought there was time to screw around and still save the planet.” And if you are older, with a grown-up child who once put you through hell, then I am definitely your son.

“We don’t mind what you do with your life,” my parents told me, “as long as you are happy.”

I wish you had not said that. It was not possible to be happy by deciding to be so. It was, however, all too easy to choose to have a laugh. And as we emerged from university the culture told us clearly that youth was everything. It was not that we were rebels without causes: we saw a score of revolutions and across eastern Europe millions marched, demanding Coke, Mercs and MTV – clearly everyone wanted to be us.

We were also “what the world is waiting for” as the Stone Roses put it. We were the golden commodity and the most prized consumers. And boy, did the world make the most of us. The satellite channels, commercial radio, the swelling newspaper lifestyle pages, the endless supplements, the music industry, the PR industry, the labels and brands, the flowering of youth TV and the invention of lad mags all pimped us to ourselves.

It was because we were so knowing: overfamiliar with the grammar of growing up. We knew we were destined to mess around a bit, smoke a bit of dope, graduate and start selling out as fast as possible. In the West, personal wealth rocketed. We took out student loans and hung onto our railcards for years. We were in no rush to join the dance of nine-to-five life.

We were leaderless and rudderless but not quite without idols. In 1993, my first year at university, Edinburgh students debated changing the name of their union building to River Phoenix Hall, in honour of an actor had who died from a drug overdose. I have written a book (Truant, published by John Murray) about what we did and why, and what it did to us. If you ever hear of it again it will probably be as “a book about dope”, although that is not its point. It may have been lazy, boring, weak, greedy, cowardly, clichéd and wasteful of me but cannabis was a large part of my response to that time and runs like a sticky green thread through much of my generation.

It was fun, it was cheap, it was communal, you did not throw up and it was cool. “They” did not want us to take it, but fines, prison and records did not put us off at all. Noel Gallagher of Oasis caused “outrage” when he said that for most of us, taking drugs was as common as having a cup of tea. I am pretty sure that I had more spliffs than cuppas during the 1990s. They barely seemed to count as “drugs”.

“Experimenting with drugs” is an arch, judgmental phrase, the sort of language my headmaster used as he threw me out of school. But it is accurate: a broad slice of my generation, the largest proportion ever to do so, experimented on ourselves with drugs.

The 1990s were a very good decade for dope – less harmful than alcohol, less addictive than nicotine. What a stunning slogan that was and what a brand, too. Those spiky little leaves, as ubiquitous and recognisable as McDonald’s golden arches and more politically correct.

Usage soared and convictions, too. Thousands of us were criminalised and many went to prison. And we who were muted about so much at last deigned to raise our voice. “Not fair!” we shouted. So Channel 4 staged Pot Night, an evening of celebratory cannabis-based programming. We cheered and watched it, stoned.

The Liberal Democrats voted to decriminalise pot. Our dealers were our best friends. A dope smuggler, Howard Marks, became a sort of national hero.

Just illegal enough to seem naughty, just accepted enough to seem safe: dope could not have been more attractive to me if it had tried. As it became entirely unremarkable, so they made it stronger and more addictive. I met skunk in 1996.

“We took so many drugs,” says Scott, 33, a proud father who runs an educational theatre company. “So much. But in our group it was you, the heavy dope smoker, who came off worst.”

The book tells of the crimes and betrayals that I committed, of the endless lies I told, of complete derangement and degradation, of mania and psychosis. Of course, it might well be that I am one of life’s black apples, a bad sheep, a waster and a fool. But before I got into dope there was no indication that the well brought up, academically able, happy, active and popular boy would end his twenties with convictions for taking without consent (milk float), theft (300ton crane barge), taking without consent again (car), arson (the scorched door of my first employer’s office, although perhaps it should have been criminal damage, as I had no intention of burning anything down) and two cautions for dope.

And that is just the stuff they will put on my ID card. I am far more ashamed of the moral and emotional crimes I committed against the trust of my friends and the love of my family.

There was no hint, either, of the manic highs and eviscerating lows that awaited me. “You were a happy and well adjusted young man,” my university tutor said when I went to her in terror in the middle of my first depression. “But whatever is happening to you will keep happening until you find the cause and address it.”

It took years and thousands of pounds and nights on the street and ruined relationships and the most unlikely of redemptions – working in a chaotic pub – for me to address the symptom, smoking gently between two fingers of my right hand. It took years for me to take the one piece of advice that I least wanted to hear, when it comes to dope: “Just say no.”

The most terrifying thing about drugs is the way they can strip your soul naked, unconcealed to itself. There are various terms for it: a bad trip, or “a whitey”, or “the fear”.

My father put me on the road to recovery the day he shut his door and let me go, mad-eyed, without a penny. But perhaps, with our own children, we will be able to prevent things going that far. Perhaps, because we are at last being honest about dope, and distinguishing between the minority like me who shouldn’t take it, and the majority, like the home secretary, who dabble harmlessly and move on, the culture is wising up.

When I was young I wanted dope to be legalised so that I could get it more easily. Now I want it to be legalised so we might be frank about its increased dangers, cover it with health warnings and rob it of its cool.

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