Nights are so full of thoughts. It is like you have empty space inside your head at the day time and suddenly a stork drop in your brain from nowhere. But obviously it's not suppose to think of something meaningful because it always like a see-saw. Either it goes to the past or fly over to future. Anyway that illusion of thoughts never going to bother your actions another day. As I already said, the space will be empty at the daytime.
Write what you know. The value of an idea lies in the using of it!