I just want to state that not everyone has situations where they speak fluently. I don't have a situation where I'm fluent. There's definitely an aspect of stuttering that isn't just in your head and it can become automatic or semi-automatic for some people over time as it becomes muscle memory. The cural diaphragm freezes due to your mind going into a cycle of panic. That's where the issue is, panic affects your breathing and therefore your speech, this happens to anyone but has a larger effect on those who stutter. This is *A* reason why you wouldn't be fluent in some situations compared to others.