Heron’s Emotions

Why does Heron go to such lengths to try and conceal his emotions from Trissy? Is it because of survivors guilt over the fires when he was a young man? Is it because of his feelings for Grabon and some of the other dragons? Is it because of the emotions that come into play because of his exposure to such a different culture and his feelings about being human with dragon knowledge? Or is it human to try and control what we can and horde our own hurts small and large?