Writing - You're in it

  I’ve tried to explain the mindset of being an author, and yet the narrative is controlled by the characters in the story rather than by you.

If you think about it, it is perfectly logical. When you create a

 character, you don't just create the physical or even a convenient set of behaviours, but you also produce a psyche that will enable the character to operate within the story. So, an aggressive nature,  or high intellect, or supportive traits. In other words, you make them human. 

In reality, I believe that while you are writing, you are employing several aspects of your brain and its functions. While in that concentrated state, you are empathising with two or three characters in your story, then your own reality becomes secondary to the story, and you have some kind of out-of-body experience. This is then explained as the story characters taking over the narrative. I offer this explanation because the alternative is not possible. In support of this phenomenon are esteemed writers such as Ian Rankin (Rebus novels). 

So being taken over psychologically is ok. That may sound strange, but it can be seen as a test of the quality of the people in your story. 

It is acceptable. 

God Bless