I think most people have difficulty connecting words and thoughts together fluidly. This is why not everybody is a talented speaker, like Oprah for example. It takes skill. For stutterers, our pattern of thinking is different. Instead of just speaking our thoughts, we anticipate we are going to stutter speaking those thoughts. So in our mind we are frantically thinking of what words will be easiest to say. All this happens in a matter of a second. I'm even having a hard time trying to explain this because I don't fully understand it myself. But yes, I have felt difficulty connecting words and thoughts together, but I think it is different when fluency is involved.