What do you want to be when you grow up? When I was about 10 I answered with complete confidence: I wanted to be an air hostess.

That was the last moment in my life I’ve felt such certainty about my career. As a teenager I adopted the more sensible, if slightly vertiginous, position of not having the faintest clue. All I knew was I didn’t want to be a chambermaid, or a filing clerk in a psychiatric outpatient department, or work selling woks at Habitat. These were the only trades I had any experience of and found none of them satisfactory.

Even now I’m not quite sure what I want to do when I grow up. I’ve been stuck these past few decades in a remarkably pleasant siding, but still hoping that the answer to the question will one day come.

Thus I’m quite unmoved by last week’s supposedly worrying survey showing that 13 to 17 year olds in Britain want to do the “wrong” things. They want to be teachers, doctors, lawyers, shrinks and hacks. This is meant to be bad because there aren’t enough jobs for them. A fifth wants to work in culture, sport or media (God help them), which together make up barely a 50th of the jobs going.

The only thing that worries me about the survey is that someone thought it worth the trouble and expense of putting the question to 11,000 teenagers. It’s not only pointless asking them, it’s damaging. The question assumes that the right career is waiting to be found, just as Mr Right is. In fact, the process should be much more trial-and-error than follow-your-dream, especially as a teen dream is likely to turn out a dog. If I’d followed mine I’d now be 30,000ft in the air saying: “Would you like ice and lemon with that, sir?”

Worse still, the question is outdated. These teenagers have 50 to 60 years’ work ahead, and the best way to survive that is to do lots of different things. Which means they can afford to get it wrong a few times before finding something that suits them.

The results are not all bad. No one wants to work for banks any more – surely progress. Even the private school kids (whose parents are likely to be bankers) don’t fancy it. Fewer still want to go into public relations, let alone human resources. The latter was one of the least popular trades of all, along with working down the mines and in a call-centre. Instead they all want jobs that require training and brain power. UK chancellor George Osborne, should be thrilled at such ambition: he said last week he wanted Britain to be an “aspiration nation” (or what those of us who aspire to better grammar call an aspirational nation).

Yet what these kids are yet to know is how unhappy their dream jobs may make them. Lawyers are at the top of the desired list but at the bottom of most job-satisfaction surveys. Only four in 10 lawyers recommend the law to others. The rest see punishing hours, the pointlessness of putting commas in the right places and the uncongenial colleagues.

By contrast, jobs despised by teenagers turn out to be rather happy. No one, it seems, wants to be a chef, but this is one of the jolliest jobs going, according to a recent survey by Forbes . Secretaries and tellers apparently have a blast.

There is no point in trying to tell the kids this. The only way to find out is by doing. And this is the one thing no one seems to have the stomach for any more. My own privileged kids don’t do Saturday jobs and, rather than do proper holiday jobs, they spend time as unpaid interns in “dream” jobs, lusting after fantasy positions they are unlikely ever to get.

From my three unskilled teenage jobs I learnt a lot. Being a chambermaid was wretched: not the cleaning, but the isolation. I was the only Brit and had no shared language, or shared anything, with my browbeaten colleagues. Being a shop girl would have been better, but the manager was chaotic and used to shout. And it was so boring that one day I got into a linen basket and fell asleep.

By contrast, the psychiatric department was quite fun, as I was ghoulishly fascinated by the patients and the receptionist made me laugh. Working there I learnt the most underplayed lesson of all. The hospital was close to where I lived and I walked there. Even though I was only 19, I discovered something that academics recently did an entire study to establish: the easiest way to ensure that your dream job is a nightmare is to have a long commute.

– (Copyright The Financial Times Limited 2013)