For this one, please put on your parent hat. Or your relative hat: grandparent, uncle, aunt, sibling.
Think of a child or some children you know and love. Picture talking with a bunch of friends, someone comes up to you and asks, "So who have been the really good teachers in (child's name)'s life? Why do you say that?"
What I'm really interested is what comes right to mind. Who was a good teacher in this loved child's life--how do you know? Why do you say that?
It'll be interesting to see what themes emerge.