I wanted to write something different – to tackle the particularly cruel way that adults can hurt one another through mind games and manipulation

When you make the jump from aspiring to professional writer, you don't realise that the change is that there is no change. Not really. You can go out to interviews and signings and so forth, but when you come home again you are still just a woman in a dressing gown with a laptop putting together something that you hope will be well-received. 

After all, the book in your head is always amazing – it's just when you commit to creating it using actual words that you start to worry about it all falling apart. Weirdly, after having a successful book come out, I found it increasingly hard to write the next, because the stakes for failure had just shot up. What if the first book was just lucky, a stroke of lightning out of a clear blue sky that can't be replicated or depended upon? 

It turns out that this is a very common feeling, so much so that it has its own name – the" Imposter Experience", (as described by Clance and Innes in 1978). Someone with Imposter Experience, or Imposter Syndrome, as they used to call it, has problems believing when something they do goes right. They feel like a fraud, hence the name. 

That said, there is something about learning that your darkest fears have their own "syndrome" and Wikipedia page that goes some way towards calming them. Your neuroticism is not personal, and that's always great news. 

And it puts me in mind of what Ira Glass says about the "creative gap" (click here for Daniel Sax's gorgeous video take on this). Glass says that the creative gap happens to an artist when their taste outstrips their ability, which is what you would expect to see when someone is starting out in their craft. They have taste enough to see that their work falls short, but not how to fix it. That shortfall is called the "creative gap".

The cure for the creative gap is the same as the punchline for the old joke – "How do you get to Carnegie Hall?" The answer is practice. 

In a conversation I was having with another writer recently, she was describing the experience of being a musician. You spend your whole life writing your breakthrough debut, then you get a single year to put together the next one – that most famous animal, the Difficult Second Album. 

The Difficult Second Album happens when you are called upon to make the leap from being a committed amateur to a consummate professional, and you are conscious that your creative gap has to close up some more, and fast. 

To survive it, to find the courage to finish, you have to get in touch again with the things that made you do it in the first place. Before I sold Dear Amy, I lived to write, but it was always at the bottom of my list for the day. It was squeezed into lunch hours and commutes. It was the secret world I lived in between eleven and three in the morning, while the rest of the world slept and real life awaited on the far side of dawn. 

You do it because it's the only thing that works for you – because when you're in the middle of it and it's flying, it's really flying – and it feels like nothing else on earth. This is why it's worth the fear and the performance anxiety and the sleepless nights. You have to do it, because a life where you don't is unimaginable. You do it because, hell, what else are you good for?