So what is the point of listening if no one thinks you are listening?

Uummm...what did you just say

Listening if no one thinks you are listening can mean you are being let in on information not otherwise attainable but, more than likely it's a waste of time or for rumors sake.

You might hear some useful info that can be applied to different situations.

sometimes people talk just to hear themselves talk

So you can hear the tree that falls in the forest.