If they aren’t allowed to play British Bulldog unsupervised at seven, then they’re going to decide to throw a fire extinguisher off a building at 18

A couple of weeks ago, the inspiration of a quiff, a pair of plus-fours and a quick, cool head died at 98 in Copenhagen.

Palle Huld was well known in adult life as an actor, but had been famous since he was a boy.

At 15, in 1928, he won a competition run by the Danish newspaper Politiken to commemorate the centenary of Jules Verne. The prize was to travel, alone, round the world in 44 days, without flying – Politiken's point was that transport had grown efficient since Verne's day.

The teenage Huld's journey took him through Canada, Japan, the badlands of the new Soviet Union, and even through Manchuria, in the middle of war. He returned, 44 days later, to a welcoming crowd of 20,000 and eternal fame in his own country. The Belgian comic-book artist Georges Remi is thought to have followed the adventure closely. The first adventure of a new hero, Tintin, came out the following year under Remi's pseudonym, Herge.

I read about this remarkable adventure, wondering at an age which could run a competition to send a teenage boy alone into some of the most dangerous parts of the world. And then, the same evening, coming home from work, I saw two teenage boys, rather older than Huld would have been, walking along with their mother. They were holding a daubed banner. She had evidently come to pick her boys up from a protest against the education cuts, to make sure that they got home safely.

In the past 20 years, the cotton wool has been thoroughly wrapped around the children of the nation. Systematic adventure has passed into the hands of well-funded Outward Bound schemes, where the dangers and risks can be assessed by professional health and safety advisers. The adventure takes place under adult supervision, and a certificate issued at the end. Genuinely independent undertakings, even very small ones, have more or less disappeared.

Earlier this year, a Dulwich couple, Oliver and Gillian Schonrock, were threatened with social services when it was discovered that they were allowing their two children, aged eight and five, to walk in each other's company to school. But surely we are in favour of children's independence. Well yes, we are. There is an organisation entitled the "Walk to School" initiative. Its website "includes information on events and resources for teachers, parents, and students". Probably the Schonrocks' problem was that they did not sign up for the events and resources for teachers, parents and students. Perhaps they did not believe that they needed to fund the activities of busybodies before letting their children leave the house.

Of course, the busybodies don't believe that they have, in fact, curtailed the freedom of children. They can still do most of what they used to do, after all. A brief look on the internet will discover that there is no activity or entertainment, no matter how innocuous, which has not been surrounded by well-meaning advice and supervision. Thinking of taking your sledge up the hill, kids? Read this one, first: "A popular snow day pastime is to go sledding. What should be an enjoyable day with family and friends could turn into a trip to the doctor if safety precautions are not taken... have everyone practise getting off the sled safely... consider using helmets... sled in an orderly fashion..."

That one comes from a Fort Wayne website, but I have no doubt that a few hundred health and safety words on everything from climbing a tree to playing marbles could be found without too much effort. That raucous and naughty playground mob-entertainment, British Bulldog, which was always banned by grown-ups after a kid broke his arm playing it, has been resurrected. Only now it's called Tag Bulldog; the rules are imposed by grown-ups watching, and it is being encouraged "in an attempt to diminish childhood obesity". There's probably a quango for it.

These are the children of the Jon Venables and Robert Thompson case. The abduction and murder of three-year-old James Bulger, in 1993, affected an entire generation of parents. If a child could be abducted and murdered when a parent's back was turned for a moment, how could you possibly let them discover the world on their own? The abduction of Madeleine McCann from a locked hotel room, 14 years later, should have demonstrated to parents that there is no life without risk, and the minute possibility of tragedy can never be eliminated. But a parenting ethos of supervision and surveillance had taken hold, and health and safety had a generation in its grip.

For the sake of avoiding a terrible imaginary tragedy, adventure was largely sacrificed. The children in Swallows and Amazons would never have wanted to go boating on their own; their father would probably have been prosecuted for sending a telegram reading "BETTER DROWNED THAN DUFFERS IF NOT DUFFERS WONT DROWN"; and, at best, they might have been sent to a summer school run by a well-funded health-and-safety expert in a Helly Hansen top. Not really the same thing at all.

The ambition to hold children's hands into adulthood and well beyond has a good intention behind it. But, sooner or later, children are going to say "sod it" and invent their own adventures. If they aren't allowed to play British Bulldog unsupervised at seven, then they're going to decide to throw a fire extinguisher off a 15-storey building at 18. If they have to sit through a lecture on the dangers of snow on a hill before they're allowed to get on a sledge, then, in the end, of course they're going to chuck paint at the Prince of Wales's car and terrify the poor old Duchess of Cornwall by smashing her window. As for the good little boys and girls who have never thrown anything dangerous at anyone else, I doubt there is much future for them – never going to the park or the library alone is not much of a preparation for anything. There is a cartoon by Roz Chast, entitled Mother's Day Off, in which a middle-aged woman sits in a chair, smoking, and saying, "What's the worst that can happen? You'll break a leg. So what? You'll live." The Danes ought to erect a statue: not to Palle Huld, but to Palle Huld's mother, who let him go round the world in the first place