I imagine a lot of writers have this problem. I call them sticking points. They are little scenes or ideas you have for your story that really don’t fit, but because you love them you stick them in anyway.
I get bogged down in sticking points a lot. When I first begin to come up with a story idea, it’s all in my head. It’s a dialogue between characters, and many things happen, but none of it’s written down. However, there are times when an idea sticks with me and I determine it’s part of the story. But even as I begin to write the story, even as the characters and the story itself evolves, I am determined to get that idea in there.
For example, the revision I’m working on was originally very different because it was part of a series. (See Series-itis). It had a lot of back story and secondary characters that become unimportant when I decided to take it out of the series. For instance, the hero was once in love with his brother’s wife when they were growing up. Though in its new incarnation this piece of back story had absolutely no place in the novel, I was bound and determined that he had been in love with her and the heroine should know it.
So, I stuck it in there. And even now, realizing that it doesn’t forward the plot, develop his character, or give insight into his relationships, I have a hard time taking it out.
But, I have to. It doesn’t belong anymore. I have to unstick the sticking point.