When you're writing a book it's very clear in your mind. It's with you all the time. And then they're all too present when they're being edited, a process that carries on after they leave your hands when first the editor, then the copy editor, then the proof reader all force your attention on the text. Finally, your book has to be very firmly present when it hits the bookshops. There might be interviews or readings or talks - it's essential to know your stuff.
But after that the books drift into a sort of literary twilight. You never lose them entirely, but they fade, displaced by the new project, the new enthusiasm. Some stay alive for me because I give talks based on them, but others have no such life support.
And that's where a dissonance creeps in. When a reader buys your book, however many years after you wrote it, it is still fresh and new to them like a hot loaf straight from the oven, where to you it may have become a ghost in the autumn mists of the creative act. (Apologies for coming over a touch literary, I have just been reading Ray Bradbury, and it's hard to shake it off.)
This morning I had an email from the a reader of a book I wrote back in 1999 and really had to work back mentally to reach that book. It wasn't a bad experience - it's great hearing from readers - but it was still a shock to the system, a sort of 'did I write that?' moment. Then it all came back and I was able to answer her question. But for that brief period of time, I did feel visited by a ghost.
PS Five meaningless points to anyone who can spot the mathematical reference involving a philosopher/bishop in the title of this post.