There are times when I flat out say, "I have no idea what you are saying to me" or "I really don't know what you are asking me." It actually happens probably once a session, sometimes more. I'm not sure if that is the same thing as you are experience though.

For me, it is that feeling that I know he knows what he means, but it might as well be a foreign language to me at that moment. For whatever reason. And it works the other way as well. Sometimes he clearly doesn't get what I am saying. We just keep rephrasing, trying various analogies/examples, etc. until something finally clicks. Unfortunately it doesn't always click by the end of the session. That's truly frustrating, but it isn't for lack of effort I guess.

I don't think it is a cognitive issue on our part. It's just the nature of trying to convey feelings and concepts that are by nature very abstract and many times ambiguous.