Sometimes people say they won't post a theory because it is so OTT. Anyhow, for your amusement, or irritation, here is my OH's idea about JW. We both read that Watson may have had as many as 6 wives. It seems to me he had at least 5, so what happened to them as none of them seemed to last long. I suggested to OH that he didn't actually marry any of them. OH said he probably killed them. He gave them something to make them ill and then a quick jab with something lethal. I said that he's a nice ordinary guy so OH said he writes as if he is, but that doesn't mean anything.
This made me think of Mary. Everyone thinks she loves John because she says she does and resorts to desperate measures to hide her past. But suppose she's just using him to get an ordinary life again. After all, anyone can say they love someone, it doesn't mean they actually do and if she's been trained in covert affairs she would have been trained to act out different roles.
This doesn't solve the problem of John leaving her and baby to gad about London risking his life having adventures with Sherlock. The writers have to do something about this because it would just make him look a bit unfeeling. Therefore, if things are to continue with Sherlock and John as they do in canon, something has to be done about Mary and the baby. They will either both have to die or Mary will die and the baby will go to a relative or they will both disappear somewhere. In canon Mary dies, but we have have now drifted away from that universe with the pregnancy.
Personally I don't want to see a Mary, John and Sherlock show, with baby in a crèche or something so I wonder how the writers are going to deal with this problem. Anyone any ideas? Or will we just get Sherlock, Mary and John, which I don't actually want.