Most writers feel this, I think. I certainly do. I want to feel it. I strive to feel it. I’m talking about when your characters seem to take over and make things happen. Now, I’m not going to argue the authenticity of the feeling. It's happened to me so I believe it. Maybe it is just finding the place, the altered state, which allows you to access that part of the brain that makes intuitive leaps. Or maybe you’re connecting to a higher power, any higher power. I don’t know.
Whatever. Your characters come to life. They take you places you hadn’t thought of or intended to go and these places are the right places for your story. Some of the truest writing comes from these moments because it’s coming from inside the world of the characters and story. You aren’t forcing it.
Of course sometimes you have to force it. Sometimes you have to work things out and plan a scene and re-imagine something that’s happened that seems wrong. You do all the work, you struggle and fight, and sometimes all of that allows you to get to that moment when the characters seem to take over.
Let them. Let go.