Ideas can come spontaneously, but when you are purposely looking for an idea, you brainstorm. Brainstorming almost always goes bad in me (duh), but after it builds up from zero to something, we can't stop.
This artwork reflects brainstorming at its best. Whatever kind of ideas you are looking for, if you have find the start point of your idea, you can't stop. You get immersed in it in no time. You want to do whatever you can to capture and keep it. You probably hear some people say "you and your world" to you, that is what you look like when you brainstorming.