Responses
I can’t believe I am saying this but... Ryan left such a strong emotional/psychological imprint on Christoph by that gesture that even though Christoph might no longer associate its significance with Ryan due to his memories being erased, but deep in his heart, he likely felt a “stinging and longing” feeling.
I feel hurt for Christoph. He was happy that Ryan kissed his forehead and having tea with him but he couldn’t enjoy it before all his memories about Ryan were erased. That just too cruel. At least let him enjoy it fullest for one last time.