I took a phone call once, asking me to put Craig in detention. It was his mother. She had had enough. He had been defiant and unpleasant and she thought he should be punished, but didn’t want to upset him. She would rather I did it.

I remembered this when I saw research that said children do better at school if their life is structured at home. Is this really such a surprise? For many of us, adult life is defined by the family machine we must service, generally to ensure children are in the right place with the right clothes at the right time. But some parents don’t provide any structure. Children from chaotic homes are chaotic themselves and difficult to teach. For them, the word “no” is always negotiable. You will all know parents who have no idea of their obligations to their children. They are afraid to correct or confront them. Once these lines are blurred, it becomes impossible to teach them.

Take Kristian. He was seen on video shoplifting in the local mini-mart. The store owner had had enough of offering him a regular five-finger discount and decided, rightly, to press charges. But whenever the police called at his house, Kristian wasn’t there. Eventually, they arranged to meet him in school. At least they knew he would be there for a while. His mother had no way of keeping him in the house. She knew she should, but her motivation had always been to avoid upsetting him. The path of least resistance is very seductive.

Some parents have no choice other than to give limited time to their families. The economic imperative is too strong and times are cruel. They give in to their children because they feel guilty. They know their children deserve more, but they can’t find a way to provide it. As a result, they don’t want to deal with any upset that hard parenting might cause.

You see it at parents’ evening. You can work out instantly who is in charge. Those letters telling the school they don’t want their child to be given homework, ever, encapsulate such relationships perfectly. Better to send the letter than risk an argument. Internet access is another big issue. When children are allowed unlimited access from their bedrooms, their parents have little idea of what is going on. They don’t really want to know. But it can’t be bad if it keeps them occupied.

All children come without an instruction manual. And sometimes the best help comes from within a family. And yet for many this support isn’t there, so a sense of trepidation is established from the start. The desire for a life without arguments becomes paramount. So it is best not to know what is going on or where the children are or what they are doing. They do what they want because there is no one to stop them.

It can end with bizarre teenage ultimatums. I recall a remarkable conversation with parents about their difficult daughter. “What can we do?” they asked. She said: “If you don’t let me have sex in the house, I will have sex in the street.” And in the peculiar world they inhabited, this seemed a perfectly reasonable argument.

It is a hard job being a parent. It has its joys and excitements, but you will never find any of them if you are afraid of children. And many parents are scared of theirs.

Geoff Brookes is a former deputy head in Swansea and a part-time quality champion.