The conversation between father and son was not smooth. They too rarely spoke to each other like family, so it's no wonder they couldn't find a common topic. Unless it was a shared past.
"So you go to the Lofoten Islands. I thought you would never want to go there again."
"Me too," admitted Gustav. "But David..."
"David..."
"I don't know myself. With him I feel like all my fears aren't scary and my prejudices are silly. David... puts the world in a different perspective for me."
"It's strange, isn't it," agreed Olaf, "that it takes someone from the side, from the outside, to see our imperfections."
"I think you've always spotted mine without a problem."
Gustav's wounds are too deep to heal in one day or one month. That's why he will attack the one who hurt him the most. It's a natural reflex of self-defense.
Good, Gustav should know how to defend himself even against his own father.