There was a scene where the masked man gave zang hai a puzzle to solve, and while he was solving it he asked the question
“how many people in your household died that night?”
Zang Hai: “my household had 10 disciples, all killed by those men in black. i saw my senior gousheng’s neck being snapped. my sister and mother were both slain by the sword. that night, 14 lives were lost in total. it’s been 3,325 days since then.”
He said this with almost no emotion, because that is what his masters taught him, that there is no need to show hatred on the face, to keep it in the heart. There is still a lot of hatred and trauma inside him, and he does get emotional from time to time. He just has a different way to cope with trauma.
After the first time in the tomb, he did plead with the marquis for all the people who died, and got angry when his plea was ignored. So, it’s not like he forgot about them. In fact, his hatred must have increased more.
Personally, I feel that drama has a fast pace (which I like it), and they move on to next step pretty fast which is why you might think he is all fine and dandy.
Based on the promo material, I know there will be lot more instances when he thinks about the past.