John’s hallucinating while bleeding out. This is how I read the events taking place in The Final Problem; it’s all a product of John’s imagination, which explains the theme, the odd characterization, and plot holes. That’s why they dangled three Garridebs before us, because the whole episode is happening during Garridebs. Therefore, John mixes real words Sherlock might be telling him, with his unconscious dream.

This one goes to the lovely Jacky, who @waitedforgarridebs and thought she’d lot it, but she proposed the dream theory and we started to talk about it in THIS POST. A spark which blew into a flame. In my opinion, this is a very plausible explanation of all the facts.