With the historical fictions, I was already doing so much research, and so much of the stories was anchored by historical truth that the move to nonfiction didn't feel all that dramatic - just another half-step to the right.

I just can't fathom tweeting, and I'd rather spend my time writing a book than a blog, but I rather grudgingly agreed to a Facebook page. I had a brief, intense romance with Facebook. It's weirdly addictive, but anything that time-sucking is a danger for a writer who writes as slowly as I do. Now I post only occasionally and nothing very confessional. I think I'm carbon dating myself as I speak.

I loved short stories, and they were all I wanted to write. I love the compression of them and the exactitude needed to get a whole world into such a small space.

That requires quite an imaginative leap because it's hard for me to imagine that my biography would be of much interest to anyone, and because I'm a fairly private person, the notion doesn't appeal to me.

If anything, I've found nonfiction a little easier. You don't have to make anything up. Of course, that's the inherent difficulty as well: when you hit an information black hole, you don't get to make it up. That hasn't come up too often with this project though. I'm lucky to have tons of primary source material , reams of letters and diaries and memoirs.

I think I was also afraid of the novel. I write line by line, proceeding at snail's pace, rewriting as I go and paring the excess away. This is against all the best advice for writing long form prose, and I have tried over the years to break myself of the habit, but I can't bear to leave anything ungainly on the page and half the fun for me is that tinkering. So the length of a novel was a daunting prospect.

Practicality continues to be a challenge for me - it's at odds with being an artist. I actually had a career on stage in New York - not a brilliant career or I'd still be doing it - but I got enough work to keep my agent and my union health insurance.