David Mitchell said this quote

“ Sometimes I think that creativity is a matter of seeing, or stumbling over, unobvious similarities between things—like composing a fresh metaphor, but on a more complex scale. One night in Hiroshima it occurred to me that the moon behind a certain cloud formation looked very like a painkiller dissolving in a glass of water. I didn’t work toward that simile, it was simply there: I was mugged, as it were, by the similarity between these two very different things. Literary composition can be a similar process. The writer’s real world and the writer’s fictional world are compared, and these comparisons turned into text. But other times literary composition can be a plain old slog, and nothing to do with zones or inspiration. It’s world making and the peopling of those worlds, complete with time lines and heartache. ”