I have a theory that inspiration floats around like winged seeds, the air is full of ideas and they alight on anyone, regardless of whether you are a painter, a writer or an inventor. They just float about and pop into peoples’ heads, and sometimes they take root and produce a flower, other times they can’t grow beyond that first flash of inspiration and move on. Have you ever noticed that if you don’t use a flash of inspiration, someone else will? A story or picture you vaguely had in mind turns up as someone else’s work. I don’t mind when that happens, it just shows the seed found more fertile ground.
Jo Rowling said that Harry Potter just `popped into her head” fully clothed and ready to go - of course he did. The seed that was destined to flower into the seven Harry Potter novels knew this was the mind that would nurture it best.
I know sometimes and idea pops into my head fully formed and all I have to do is write it up or gather my art materials - if the idea lies fallow and doesn’t come to anything, no matter how often I look at it, I know it’s not really meant for me. I just caught one that was floating about, and I’ll happily let it go to find another mind. There are plenty more floating about up there, and while some are not for me, I’ll catch one that is.