I’m afraid it’s happening. The police officers, schoolteachers, even the cabinet ministers, seem younger, and I’m finally staring down the barrel of my 40th year.

Now a mother myself, I cringe at much of what I put my parents through in those teenage years. Sometimes I hear their voices in mine, and it’s not always the sweetest music. The other day my six-year-old questioned the rationale for some request or instruction and, yes, I actually said, “because I’m your mother and I said so”.

What can I do to halt the slide before the professional protester becomes Disgruntled of Little Whingeing; the music too loud and fashions too strange to understand? I find that actually talking to young people provides a useful counterpoint to that image of kids jumping on a car roof. You must know it, the scary one that seemed to appear on the news every night for years. My own little one is a good start — 6 going on 16, with strong, precocious opinions and a big heart.

“Do you have to argue about absolutely everything?” I seem to be on autopilot now. The quick wit and warm smile flash back. “Mum, we’re related. It’s in my DNA.” I don’t tell him that the authorities actually stockpile kiddy DNA these days. Looking in the mirror is a complicated pastime when each characteristic is capable of irreverent rejoinder.

Then there are other people’s children, even more of a challenge without the compensations of genetic vanity. My son recently banned me from chatting to his playmates. He found it too embarrassing, like trendy-teacher syndrome.

So my real exposure is to slightly older young people. Are they really so much more lazy, rude and troublesome than a generation ago?

I wonder. My friends’ teenage offspring seem rather nicer than I was at their age, and the young strangers that I stop on south London streets for directions are so much keener to help than my misanthropic middle-aged counterparts, no doubt overburdened with problems of their own.

Even students (supposedly the lotus-eaters of modern society) seem necessarily more world-weary than when I first set foot on campus 20 years ago. Debts replace dreams and second jobs the space for social mobility and personal growth that we enjoyed at college. These kids have grafted and been tested within an inch of their lives since the sandpit, yet Grumpy Great Britain complains the tests are too easy.

The ever-ageing population and competition for resources are only likely to increase the risk of age apartheid in a country that will no doubt need its present young generation to work harder, longer and for less financial reward to keep the baby-boomers and Thatcher youth in the manner to which we have become accustomed.

Do you remember those signs that said “No more than two schoolchildren may enter at any one time”? Well, they’re still there, but now they are accompanied by curfews and silent sirens that repel only young ears.

Ask visitors from all over the world and they’ll tell you that we are as odd in our attitude to the young as to the old. We can’t seem to cope with the mess, noise and unpredictability. My postbag suggests that adolescents are even less popular than terrorist suspects. I fully expect to see “Britain Hates Hoodies” appearing on prime time one of these Saturday nights. The judging panel of cop, editor and ambitious politician would name and shame various naughty kids. Tele-voting and an audience stoning would follow in this innovative blend of popular justice and entertainment. Premium phone rates would apply.

Don’t get me wrong. I’m as prone to fear, irritation and general grumpiness as the next person, and know that kids can be as thoughtless and cruel as the rest of us. But that’s no excuse for prejudice and collective punishment, or the blanket withdrawal of the kindness and civility that we are so quick to demand for ourselves.

When relations do break down between youth and the not-so-young, we could take a little more personal responsibility. Tough though parenting is, the state is even worse at it than we are and law enforcement the least appropriate baby-sitter.

Let’s stop blaming the young for our mistakes, large and small. They didn’t crunch the credit or wreck the planet. They didn’t choose their parents or social circumstances — though many of them act as unpaid carers for years before they even get to vote.

As someone who has the joy and privilege of working with young colleagues, I am humbled by the altruism, industry and expertise of the MySpace generation. Sharing their space fills me with endless optimism that our future might be far safer in their hands than their precious childhood ever was in ours.

Times recommends

• Think yourself slim with our hypnodiet podcast
• Why British children are pushed too hard
• So, what really makes you happy?