'The seed that sets you off'
‘I do think that sometimes the seed that sets you off on the process of writing a novel can have been around for many years, even decades, before it actually - for some mysterious reason - comes to fruition . I think it's almost a good sign if an idea has been fermenting for quite a long time in a sort of semi-conscious way.
I've learnt to distrust the staggeringly brilliant new idea that was triggered by something that happened quite recently. Ha ha! You need the dog-eared thing that's been around for a long time, quietly nagging away at you.'
Pat Barker, author of The Silence of the Girls, the Regeneration trilogy, The Eye in the Door and five other novels. https://www.penguin.co.uk/authors/16113/pat-barker.html