About a breakup, obviously, that most likely happened in London, given the bounty of images of England's capitol city. Emotionally though, its really about helplessness, the idea of the narrator, singing to Watson, the right hand man of Sherlock Holmes but also the one who narrated the Holmes stories. So the protagonist is talking to someone about his loss who is the actual narrator of the story.
About a breakup, obviously, that most likely happened in London, given the bounty of images of England's capitol city. Emotionally though, its really about helplessness, the idea of the narrator, singing to Watson, the right hand man of Sherlock Holmes but also the one who narrated the Holmes stories. So the protagonist is talking to someone about his loss who is the actual narrator of the story.