As wise parental counsel goes, telling eight-year-olds that using heroin feels fantastic isn't exactly up there with keeping wet fingers out of electrical sockets or avoiding car rides with strangers. So it is understandable that anti-drugs campaigners have hit out at telly presenter Davina McCall in the last few days, after she revealed that she had told her daughter just that.
Except for one thing – she's right. Heroin does feel fantastic. Why else would people send it swimming into their bloodstream and let it take over their lives?
"Recently, because of something on Radio 1, we had to have a drugs conversation," Davina told Easy Living magazine.
"Holly, my eldest, asked me: 'What do they feel like?' 'If I told her that heroin didn't feel nice and then she tried it and it did, she'll think: 'Oh Mum was lying.'
"But if I say: 'Heroin is so fantastic you'll want to take it again, then you'll get addicted, which is horrible,' that's honest and more frightening. Wait until they ask and tell them the truth."
As the Big Brother presenter, herself a former addict, is well aware, you don't take drugs because you're reckless and self-destructive. You take them because they make you feel bloody great AND you're reckless and self-destructive enough to make that immediate thrill a higher priority than your long-term well-being.
And this is what her critics fail to understand, but what we have to get across to the young.
One of my more strait-laced friends once told me that her father, a lovely man, had taken heroin a couple of times when he was younger. I was surprised by the revelation – mainly because she herself was so singularly uninterested in altering her state of mind.
Hadn't his confession made her curious? Well no, she said, because what he explained to her, at quite a young age, was that the heroin felt so unbelievably good he knew it had to be doing something unbelievably bad, so after dabbling twice he decided never to go near it again.
Another friend of mine, the only person I know who has worked in nightclubs for 10 years without so much as getting drunk, is often asked how her crazy work environment has never tempted her to dabble. She always tells them that her mum was an experimental hippy who, on one particularly scintillating acid trip, lay in a farmer's field for ten hours, staring at a fox.
Not that the mum reported this as an unpleasant experience, exactly, but my friend grew up firmly convinced that watching a nice big flat-screen telly in a centrally-heated living room was infinitely more appealing than ogling wild animals in fields of barley.
There are no two ways about it – drugs can be amazing. Ecstasy makes you feel so loving that you start thinking it could solve all the world's wars; you want to put it in the water supply at the Houses of Parliament. Cocaine gives you balls of pure steel and makes you feel like the most important person in the room. Heroin is central heating for the soul, "the kiss of the archangels", as Sebastian Horsley described it.
Until they wear off, that is.
One line is too many and one hundred is never enough. The coming down, and the coming off narcotics, sucks the life out of you, until you feel as if something that should be scrunched up and thrown in the bin.
So tell kids the truth about drugs. Tell them that they take you from feeling invincible at a party, all ten storeys of endless-and-forever you, to standing alone and desperate in a bathroom somewhere, clutching at your skin as you try desperately to make the floor stop shaking and the tiles stop hating you.