I’m still often surprised by my family – they think (yes, even after all these years!) that if I’m not actually engaged in the physical act of writing, that I’m not writing. But we writers know differently, don’t we? If you are a writer, you are writing 24/7. Just – always. If you’re not actually writing, you’re thinking about writing, mulling over a plot problem or planning a scene. And the solution can come to you at the most unexpected moment, just as your mind is engaged elsewhere.

I mean, sometimes you’re buying groceries, and you think, ‘oh so that’s how he got in the window without leaving any marks…’ and if you can’t remember that for later, you scribble it on the back of an old envelope or your grocery list or you dash to the loo and scratch it onto some toilet paper with an eyebrow pencil or an old lipstick (iced mocha? when was that in vogue?) from the bottom of your bag. Unless you’re a ‘literary’ writer in which case, you’ve got a notebook in every pocket, and may even have a pen.

Or…You could be watching TV and having already exasperated your family by telling them five minutes into the two hour murder-mystery that you know who did it, suddenly your attention is caught by a seemingly trivial incident and you think, ‘ah yes, and that’s how Mrs Amundsen got to the airport without the postman seeing her leave the house.’

You don’t even know you’re doing half the time. Every time someone tells you they can’t take medication A with medication B because of their heart condition, you file it away. If someone gets out of the shop without paying, you file it away, and of course as you get older these mental files take up a lot of room so you start writing it all down until a stranger stumbling upon your ‘musings’ phones the police to report a potential mass-murderer. My mind plays over endless scenarios of ‘alternatives’ – what might have happened if that didn’t happen…

I even sit in front of the TV with my Kindle ready in case I need to make some notes on Evernote – it just saves all that effort of getting up and looking for a scrap of paper. Recent notes include: stuff from the programme about Shakespeare’s mother, Mary Arden, and her duty as executrix of her father’s will of taking the fourpence her father left to everyone in the village/locality who did not have their own team of oxen for ploughing; Joe Kenda on Homicide Hunter explaining about how if a person is shot when they’re standing up, they always fall backwards with one leg crossed over the other at the ankle, that’s called ‘dead man’s fall’; or how although large calibre bullets pack a lot of power they tend to go straight through the body whereas small calibre bullets are slower, smaller but get lodged in the body and cause relatively more damage that often can’t be repaired quickly enough by a surgeon and so are just as dangerous; or that in medieval times, artists used to grind up real lapis lazuli to create that bright clear blue you see on paintings – and because it was ridiculously expensive, they reserved it for high-status subjects – the Madonna, or an official or royalty.

Now if I could get all that stuff into one book, that would be a ‘right riveting read’ as the tabloids used to say.