The week starts well. My debut novel, The Miniaturist, is a year old. On the anniversary of its publication, my friend Patrick the bookie sends me a message to say a horse called Miniaturist is running at Sandown. I’m not normally a betting woman, but I decide to have a punt. An hour later, Miniaturist has won and I’ve collected 125 quid. Ain’t it a glorious feeling when your horse comes in?

Things decline a little after that. After nine years not driving, I’m back behind the wheel and taking refresher lessons from Silvano, a Venetian south-east Londoner with a bullish prognosis for getting me up to speed. We pootle around in the small Japanese teapot he teaches in, and witness a motorcyclist spitting through an open car window. As we recover, Silvano tells me a tale of how a woman rammed a stiletto into the side of his friend’s head as punishment for being a road hog. Why is driving so hideously transformative? But still, I want the freedom of a car, so I nod, grit my teeth — and wind the window up.

Having just completed a second novel, my suspicions have been confirmed: writing is sedentary and lonely. To combat the first problem, I sign up to an exercise class called LBT, which I wish was an acronym for Lettuce, Bacon and Tomato, but, alas, has more to do with the flabbier parts of my anatomy. I arrive, astonished to see the woman next to me, 60 if she’s a day, lifting ten times the amount of weight I can manage. Steel Granny catches my eye, triumphant.

The second issue — that of sustained isolation — is a much harder nut to crack. You cannot write a novel by committee. Before I was published, my professional career was conducted in gregarious rehearsal rooms and communal city offices. These days, working from my writing shed, I regret the lunchtimes particularly, because there’s no one around to play table-tennis with me in the garden. Then the phone rings: it’s my editor at Picador, and as we brainstorm for two hours on how to make the second book fly, I feel less alone.

Fun lunch with a friend who works in the movies. We laugh about how, in Los Angeles, if you have a glass of wine at lunch they look at you askance, and yet everyone pops pharmaceuticals like Maltesers. We talk about social media — Twitter in particular. Old enough to have grown up without the internet, and yet young enough to be adept users of it, we’re wary of what this form of instant communication is doing to our psyches. I like Twitter when everyone is funny and posts links to interesting articles, but this sense of being constantly on show, of investing energy into a virtual self — are we on the crest of a human revolution, or are we just mugs? Five years ago, I committed ‘Facebook suicide’ and never looked back. Whatever Twitter is, it’s exhausting being constantly available, and I pause my account for a nice long breathe.

The writing of book two has been a psychological slog, but there are lovely benefits from The Miniaturist being a bestseller. I once joked to the jeweller Alex Monroe that he could miniaturise the 17th-century doll’s house that featured in my novel. A year later, we are having dinner, and he places a jewellery box on the table. My breath stops in my throat. A tiny Amsterdam canal-house sits glinting silver in my hand, not much bigger than a postage stamp. It even opens up, revealing the interiors. A testament to Alex’s great skill, it’s a thing of beauty.

To the Pan Macmillan summer party at the RIBA. I dress in the colours of my book cover (blue and gold) and wear Alex’s miniature around my neck. Revellers get drunk and indiscreet, which seems par for the course at publishing parties, but they have a lot to celebrate. I catch up with booksellers I’ve met along the way, all wanting to know when the next novel will be ready. It’s the performer’s paradox: the interest cheers me, and it also makes me feel slightly sick.

The week ends in Kent, on a sunset balloon ride. The noise of the cold-air fans as we try to get the balloon airborne is delightfully alarming, as is the rocking of the basket as the contraption rises with one man still hanging off the end. Once in the air, and all safely in, we drink champagne out of steel flutes and watch the Weald unfold beneath us. It’s so peaceful when the gas canisters aren’t in use; we brush treetops and scare rabbits, and delight in the people running out of their houses to wave. The world and its noise seem far away; it’s a beautiful mode of transport. I consider that, even if Silvano offered me lessons in a Ferrari, I’d rather have the balloon.