My 18-year-old was showing some parents round his school recently.
'And what's the school's policy on drugs?' said the father.
My son thought about this. Was there more than one answer? 'They don't allow it,' he said.
'Ah,' said the father, nodding wisely. 'Right.'
The whole question of what should and shouldn't be allowed is in the news a lot at the moment.
The war on drugs doesn't seem to be working.
Ten years ago in Portugal, drugs were decriminalised. Drug-users were given medical treatment. Heroin use fell by a half.
'Maybe it's time we made drugs legal in this country,' said my eldest over breakfast on Saturday morning. 'Imagine if you could just buy them in the shops.'
I had an uncomfortable mental image of cocaine on sale next to Shreddies.
'I think people want to protect the young,' I said. Just that day I had read the horrible story of 16-year-old Joe Simons who died after taking ecstasy in a nightclub in Bristol.
'But there's more crime and violence associated with alcohol than drugs,' said my eldest.
He's right, I think. But I find it hard to compare the two. A bottle of gin looks all sparkly as if it's ready to launch a party. Drugs make me think of misery and addiction.
'The thing is,' I said, 'that alcohol has been around a long time. We know the effects. We treat it with respect.'
He looked at me. 'Do we?' he said.
It so happened that I was nursing a slight headache that morning owing to a somewhat riotous evening at my friend Jane's house the night before.
'Yes,' I said firmly.
Do what I say, not what I do.