Sometimes while driving on a long trip I end up caught in a thought exercise. A creativity game that we can call “You know what would be really cool?”.
Then I try to think of something original. A movie, a game, a book. It’s also a world-building exercise. Then after some mashing of different genres and elements, I always come up with the same idea: “a space opera that’s also a western and that’s also a samurai movie”.
Sometimes I spend a bit iterating on this idea until I’m interrupted by some background thought that screams “Star Wars did it first!”.