Carol's addicted to Countdown

Then there is the production team, who've been with us for years, and our producers, both of whom are former Countdown contestants.

And then there is our audience, our lovely, loyal Countdowners who come back to us day after day, week after week, year after year.

They have seen me fat, thin, pregnant (twice), tired, lively and through it all they have put up with - especially in the early years - some truly dreadful outfits.

And still they watch. The secret of Countdown, you see, is that it is completely addictive, at least for those people who like doing anagrams and mental arithmetic.

With most quiz shows based on general knowledge, the audience playing along at home can only get their answers either right or wrong.

But with Countdown, there's a real sense of involvement, particularly if you sit down to watch it with a pen and paper at your side.

It doesn't matter if you are getting only four-letter words while our champion is delivering seven and eights, you're still playing the game.

That is why all over the country, at 3.15pm on a weekday, you will find everyone from exhausted young mothers to college professors, students to royalty - or so we are led to believe - taking the phone off the hook and settling down for 45 minutes of fun and games with old 'Twice Nightly' Whiteley.

And yet, for me, the terrifying truth is that Countdown could so easily have happened without me.

If Mum and I hadn't suddenly decided to move to Leeds in 1982, soon after I graduated from Cambridge; if Mum hadn't read an article in the Yorkshire Evening Post about the problems Yorkshire Television was having finding a woman to help with a numbers game on a new show; if she hadn't forged my signature on the application letter she wrote for me . . .

Yes, that's right, Mum forged my signature. She had drafted a letter purporting to come from me, saying how I was absolutely brilliant and just the person they were looking for.

It was so over the top I refused to sign it. What was the point? Back then, TV shows were presented by real stars like Bruce Forsyth, Jimmy Tarbuck and Michael Parkinson, not 21-yearold girls with a third-class degree and a job in a frozen peas factory.

But Mum was having none of that. She forged my signature and sent the letter. And not a day goes by without me thanking God, and her, that she did.

She was right, though, about me loving mental arithmetic. I am not a mathematical genius, but I have always been good at working out sums in my head and doing them fast.

One of my earliest memories is sitting in the nursery department of my little Roman Catholic primary school in Rhyl, North Wales, with Sister Zeta giving me sums to do and little, three-yearold me always wanting to do them faster and faster.

A few years later, when I was in the primary school proper, another of my teachers, Mrs Wynne-Jones, wrote in my report: 'Carol has a computational ability with numbers that could prove profitable in later life.' Totally thanks to Countdown, she was absolutely right.

This ability with sums brought with it an advantage that I wasn't really aware of, even when I'd got the job. Because I was the girl who did the sums, I was never the glamour puss.

In the early days, we had gorgeous girls like Cathy Hytner, who was a model, and beautiful Karen Loughlin, who went on to marry the footballer Graeme Souness, to put up the consonants and vowels.

And, in the first year, there was even another girl whose sole job was to put the number tiles up. All I had to do was the sums themselves, and in the first series I even alternated that with Lynda Barrett, who had a PhD in theoretical physics.

So I was under no pressure at all to 'perform', I could just get on with calculating and learning how the business of TV worked.

The first reviews of the show were dreadful, with one suggesting that such a dull programme should be taken off the air immediately.

But to be honest, in the early days of C4, what was going out at 4.45pm, Monday to Friday, was the last of the channel's problems.

So we just got on with it, slowly building the sort of following which ensured that, throughout the 1990s, our five shows each week would regularly be the top five most-watched programmes on the channel.

I didn't get my hands on the vowels and consonants until 1987, when a drunken Christmas lunch coincided with the departure of another beauty.

'You think you're too grand to do it,' moaned John Meade, our producer. 'No I don't,' I replied. So I did.

Countdown paved the way for me to many other TV opportunities - Tomorrow's World for the BBC, current affairs, light entertainment, other quiz shows, property programmes.

Every now and then, a producer would try to get me to give up Countdown, saying that they couldn't have one of their serious prime-time presenters still putting up the letters on a daytime game show.

And each time, I told them the same thing: oh yes you can and, no, I won't give it up.

Of course, now and again, some critics would say I was on TV far too often. But whether they were right or wrong, I certainly won't be on that much in the near future.

Thanks to the security that Countdown offers and the fact that we record five 45-minute shows every studio day, I've been able to scale down my other TV commitments, which allows me to spend much more time with my children.

Because you don't need to be particularly good at mental arithmetic to know how quickly they grow up.

So for now, and for the foreseeable future, I am sticking with dear, lovely old Countdown. Its French equivalent, Des Chiffres Et Des Lettres, has been on air for nearly 40 years.

But if someone is still asking for 'two from the top and four from the bottom, please Carol' when I'm 50, I'll be a very happy and very lucky girl.