you are getting sleepy
Aside from the validating which always works and which can be gone into greater detail if necessary, I like the idea of the theory where you mimick the body postures and slight moves of the person you are listening to. Its actually supposed to imprint them onto you and they become attached. I have never tried it but I am sure there are subtle ways to do it. I'll look into it a little more.
If it works you may be able to say less and just move more and get a trusted supporter for later education.