I like to think that after everything that happened at Sherrinford, John and Sherlock sat down and had a little chat. Maybe they were working on renovating the flat, maybe they were just having dinner, I don’t know. But John just casually brings up Molly and how real the “i love you”s sounded. Sherlock brushes him off and continues doing whatever, but John keeps going back to Molly and how no human has ever gotten that emotion our of Sherlock. The pain and rage of the coffin smashing, the genuine fear for her safety. He went there for Molly Hooper. Sherlock went full human for her. Messy, irrational, helpless human.
What if phichit turned into a rock?