A YouGov poll that has just been released rates being an author the most desirable job in Britain – with 60% of people saying they’d like to do it for a living. This is a 24% higher than those who want to be a TV presenter and a remarkable 29% higher than those who want to be a movie star.

The mind boggles – or it would if authors didn’t spend a good majority of their time assiduously, and at tedious length, trying to avoid cliches. The fact that people fantasise about being an author only proves how little they know about the reality of the job – or how under-read they are in one of the greatest of that profession, George Orwell.

It was Orwell who wrote this description of the novelist: “All writers are vain, selfish and lazy, and at the very bottom of their motives there lies a mystery. Writing a book is a horrible, exhausting struggle, like a long bout of some painful illness. One would never undertake such a thing if one were not driven on by some demon which one can neither resist nor understand.“

This is not a view of writing that occupies a great deal of space in the popular imagination. On the contrary, authors are seen as rather serene, noble characters, licking their pencils, perpetually looking out the window for inspiration – which always comes – and floating in a bubble, enjoying an Olympian perspective on the world, not bound to the nine to five like the rest, but picking beautiful sentences out of the air like passing butterflies, which they trap and affix decoratively to the page.

If only it were like that. Some writers do, I admit, talk up the delights of creating fiction. All I can say is, I have been writing books for nigh on 20 years now – and it has not been out of choice but for exactly the reason that Orwell describes – “driven by some demon which one can neither resist nor understand”.

I have on more than one occasion longed for a different way of making a living, a hope that I understand now is entirely in vain, as it is my only marketable ability.

I have enjoyed modest success, winning a few prizes, being shortlisted for a few others, and at times – now long gone, along with the book industry that existed then – pocketing generous advances from publishers. And it cannot be denied that being a writer has a lot of compensations.

Writers get to lay out their vision of the world, which, for some reason, feels important to them – although, as Orwell also observed, this may be indistinguishable from the baby’s cry for attention. At the best moments, their work flies above craft into art. They are held in popular esteem, it is true. And they control their own time to a far greater extent than most wage slaves. Staring out the window also certainly come into it – a lot.

However, as I emphasise to the fledgling writers who come and attend my Guardian Masterclass courses, writing novels for a living is hard – unimaginably hard, for those who have not tried it. I cannot imagine that it is less complex than brain surgery, or, indeed, the proverbial rocket science. To master dialogue, description, subtext, plot, structure, character, time, point of view, beginnings, endings, theme and much besides is a Herculean labour, not made more appealing by the fact that you always – always – fail.

Any author will agree with the statement that a work of art is never completed, only abandoned. And, as perfectionists, we always fall well short of our goals. We live with failures, even when we are successes – because we have the whole weight of literature standing behind us, mocking us with greatness and shadowing us into insignificance.

Being a writer also involves a tremendous amount of rejections – all the prizes you felt certain to be shortlisted for and weren’t, all the ones you were shortlisted for and didn’t win, all the TV and films rights that were bought for your books and never made, all the copies that you didn’t sell.

Meanwhile, you have to deal with the envy of watching your rivals – and authors see rivals everywhere, however much they deny it – being apparently more successful than you (naturally, you don’t pay any heed to the invisibly large majority who are less successful). Writing is not a convivial, supportive business – as John Dos Passos observed: “Writers are like fleas, they get very little nourishment from one another”.

It is frequently lonely. It is insecure – and not just financially insecure, but because the fact that you have written one good book is no guarantee that you will be able to write another. It plays havoc on relationships – because most writers are extreme introverts, who, when in the middle of a work, barely notice the rest of the world exists. When you are successful, you can quickly become vain and narcissistic. When you are not, depressed and despairing.

If people think I am lucky to be an author, I understand why. I do feel I will leave some kind of small legacy behind me when I go – a body of work that amounted to something. I know it counted for something, because I still get letters about my books thanking me for them, and appreciating, in some way or other, the light the reader felt I helped shed on their world. It is, I still believe, a noble profession, and there is nothing – given my limited range of talents – I would rather do.

But if I were honest, if I were offered the possibility of swapping with George Clooney, I don’t think I would hesitate for long. In fact, even a taxi driver – standing towards the bottom of the YouGov poll at 13% – often seems more appealing.

Writing is not a choice, it is a calling – and for me, one that extracts a price that people who imagine the glamour of the job never quite grasp. It’s just as well – if they did they might never start.