Here's David Cameron, apparently trying this week to claw back the Tory grassroots support which has been alienated by his milk-fed complexion and Notting Hill hair: "I think we'd all concede that something has gone seriously wrong with the spirit of health and safety in the past decade. When children are made to wear goggles by their headteacher to play conkers … When village fetes are cancelled because residents can't face jumping through all the bureaucratic hoops …"

There ought to be a word for the kind of stories that sound like the Daily Mail invented them, even when you're not actually reading them in the Daily Mail. Immediately, the Institution of Occupational Safety and Health issued a statement in which Cameron was politely but pretty firmly accused of reheating old myths. This infamous conker event occurred five years ago, one time only, not as a result of health and safety legislation but because of an overzealous headteacher.

How do I know? Did I hear it on Radio 4? Well, yes, initially, but that set me to thinking it would be interesting to collate all the myths around health and safety. It would be interesting to see the range of activities that are so treasured by the enemies of occupational protection that they're willing to stretch the truth, or just make things up. I wonder how I'm going to get hold of this information. It will take more than a quick search engine, I'm thinking. This will take serious spadework. I might even need to get a young person to help me.

Nope. These stories have already been yoked together and arranged neatly by the Health and Safety Executive website. The conker story was October 2004. The village fete story was July 2009. Not only are the myths chronologically arranged and summarily debunked, there are even posters you can download, print off and stick up to brighten up your workplace while reminding yourself and colleagues that none of this stuff is true.

So what starts off as rather a mild story – David Cameron's Speech a Little Bit Lazy Shock! – turns slightly bizarre. He appears to have taken a clutch of events that supposedly exemplify the wrong turns this country has taken, and not only are they not true, they're the very examples the HSE has chosen to illustrate that some people spread stories about it that are untrue.

It's almost as if Cameron is playing an elaborate double game, in which he makes a dim-witted, saloon-bar argument to one chunk of constituents, while giving a knowing, conspiratorial wink to his savvier supporters who know how to use a computer. The HSE itself won't comment on Cameron's speech on the basis that it would be inappropriate to give a view on opposition policy. But when a senior politician peddles a line that your own website already identifies as well-worn myth-making, I should imagine it's quite hard to make a remark that would be appropriately respectful.

Interesting themes emerge from the HSE's list of myths. There's a load of stories about the health and safety threats posed to activities we can loosely term "old-fashioned English childhood" – the aforementioned conkers, donkey derbies (kids not being allowed donkey rides, having to use inflatable sheep instead), bonfires, snowballs, pancake races. It reminds me slightly of the heavyhanded, hyper-nationalistic propaganda you see as a nation prepares for war: the dangers are minor enough that they don't need to be substantiated, but the underlying message is that the enemy (here, the government) deplores the very things that made you, seeks to unpick the innocence of your childhood and, in the same swipe, unmake the foundations of your (much-prized) nationality.

There's another very marked killjoy theme – mortarboard-throwing banned at graduations, hanging baskets banned, earplugs mandatory at rock concerts (these are all myths, remember) – which casts the authorities as mindlessly, Cromwellianly opposed to pleasure. (They'll ban Christmas next. They've already done for the dancing bears.)

Contrast all this with the statutory instruments that have been the concern of health and safety over the past three terms of government: four regulations about biocidal products (like pesticides, except – well, if you are using biocides, you should probably look this up properly); an anthrax prevention amendment (which totally ruined my pin the anthrax on the donkey event); five small changes to the labelling of chemical hazards. I don't really need to go on, do I?

As a rule, all such legislation is aimed at protecting employees from workplace hazards. There's very little fun-smothering. What's more, where there is a nub of truth in any of the stories about health and safety (one council did temporarily ban hanging baskets), it's not the legislators who are behind it, but day-to-day killjoys, over-interpreting the law because they're desperately cautious or destructive. Those people have always existed, and they will exist, whatever the government.

There's another thing that puzzles me about Cameron's rant: I wouldn't have thought there were that many votes in this issue. But, I suppose, in times when nobody can realistically promise to spend any money on anything, politicians have to take their crowd-pleasing where they can find it.