During Bible Study, we were discussing a myriad of things about the passage we were reading. At one point, we were talking about arguments and how that prevents people from working together, and I randomly started laughing. It described the current situation in my story perfectly.
When you're writing, you create characters. Their personality and backstory starts to take shape in your mind. A character is both a part of the writer, and separate from the writer. They exist in the writer's mind, reflecting various aspects of the writer's own personality, but also reflecting things the writer is not. Sometimes, the characters become somewhat of their own individual. This means that the character will not always do what you expect them to, or what you want them to.
For example, my main character and his baby dragon are traveling with two people. One person is fine with them, while the other doesn't want to be traveling with them. She hates dragons, and she doesn't like or trust the stranger who brought this dragon with him. I want her to warm up to these characters and realize they're not so bad after all, but something inevitably happens, and they end up arguing again. I set up scenarios that might lead somewhere good, and the characters make it ugly. Finally, my main character grew so tired of being berated and criticized, he decided to leave and go without them. Not what I wanted him to do.
I have all sorts of plans for my characters, but when I give them a chance to act, they take a totally different route. It reminds me of all the instances when God comes up with a master plan for us, and we try to do something else and mess things up. Just a small taste of the frustration He must feel when we think we know what's best for us. Now I have to find a way for my characters to return to the path they were supposed to be on.