Lorrie Moore, 67, is one of America’s most original, agile and diverting authors – a short story writer, novelist, critic and essayist. I Am Homeless If This Is Not My Home, her fourth novel, is possessed of a feral magic and is a fantastic provocation. Sad, funny and teasingly gothic, it introduces Finn, who is a lovable oddball, along with his mentally vulnerable, wildly charming and recently deceased ex-partner, Lily, who comes back into his life – and her own – in the most unexpected way.

Are you as good at amusing yourself as you are at amusing us? Your novel made me laugh aloud…
Like the author, a narrative has to breathe. Moments that are amusing within the story are like moments in life itself: a bit of oxygen in case the rest is getting too glassy or overheated. I discover moments at my desk as I go along and, sometimes, I do amuse myself. I’m glad you laughed because a lot of the story is full of despair.

I see that but am tempted to believe – to corrupt Philip Larkin’s famous line – that what will survive of us is not love but jokes. Yet, comedy aside, how much do you torment yourself as a writer – would you describe yourself as neurotic, self-doubting, or none of the above?
As a writer, I’m really not sure. I’m a little tormented in the time-management department. And as a housekeeper, I’m definitely tormented. But neurotic comes on a spectrum I assume we are all on somewhere.

Inspired by your plot, I find myself wanting to ask if there is a sense in which we carry the dead with us – departed friends and family?
Yes, I imagine we carry the dead around with us constantly. And sometimes it is out of missing them but probably it is also out of disbelief that they’re no longer alive. That was why I made Finn a doubter of official stories in other categories as well.

I love Finn’s doubt and hugely relished the epitaph you proposed for his tombstone: “Well, that was weird.” And here is a tricky question for you – could you offer me an epitaph for yourself?
“Books available!”

You have an affectionate, penetrating and unafraid take on madness and find in Lily a self-destructive charisma – have you come across Lilys in your own life?
Well, Lily is an invention designed for Finn, who is also an invention. But that is not to say that there are not impossible people in my life. But then again, everyone has those (books available!).

On the subject of madness, I keep sensing your wish to make this most human of afflictions more openly understood and (literally even) embraced?
With regard to the Finn-Lily relationship, Finn loves Lily but without understanding her completely. That may always be the way. Understanding someone 100% is probably an illusion. And madness can be seen as a stand-in term for the parts you don’t comprehend. I think those who suffer from madness know they are not completely known.

Was it a challenge to get the tenderly macabre tone of the book to stay tender and not flip into the ghoulish?
Tenderness is, I suppose, the driving force and everything else – the humour, the horror, the anger, the southern gothic – festoons it.

At the same time, you are so spot-on about the possible difficulty of talking to the terminally ill – as if death were potentially a social embarrassment?
People want to say exactly the right thing to make up for lost time while the clock is maniacally ticking. It is a form of performance anxiety but much deeper in most cases: a desire to bring the profoundly inner to the outward exchange – yet with unconfident skills and rusty tools. Or tools still sealed in plastic and cardboard.

How much, if at all, do you think your writing has changed over 30 years or more
I have no idea how my writing has changed because I haven’t gone back and studied it. I hope it’s got better, but if not, I’d rather not know. I also suppose the changes in one’s work reflect the changes in one’s self, one’s life, as well as changes in the world.

And that pre-empts what I was about to ask next: how much have you changed yourself since you started your career?
My cooking skills have probably declined – I grow bored chopping things and so now avail myself of pre-chopped produce. I fear this is a metaphor for shortage of time and energy and elegance and deep, underlying commitment. I used only to sit in rocking chairs if I were holding a baby that needed rocking. Now all I require is a glass of wine and a televised weather report. I have crossed things off my bucket list not because I have now done them but because I know I never will. So I’ve not really improved. But I could still turn things around. I think. That said, very little in this novel is pre-chopped.

What’s the last really great book you read?
Well, I teach, so I’ve had Alice Munro and Edward P Jones on my syllabus. Those would constitute great books – All Aunt Hagar’s Children and Munro’s Selected Stories.

What do you read when times are hard – for boosting or consolation or amusement?
I tend not to reread when times are hard. I feel that one must find something new. So here are two new books I found to be good company: Lauren Oyler’s No Judgement and Miranda July’s new novel.

How do you organise your books?
Alphabetically and by genre.

And what are you planning to read next?
I’m going through Jenny Erpenbeck’s books, one by one.

Is there any fictional character with whom you particularly identify? Go back to childhood reading if you prefer…
Everyone identifies with Jo in Little Women. I identify with Beth, the sickly sister who dies. Also? Bambi’s mother.

• I Am Homeless If This Is Not My Home by Lorrie Moore is published by Faber (£9.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply