I’ve been thinking more about this—this being Sherlock-and-John in this scene, and in general—because it’s so weird, really.  

John’s a strong, independent, BAMF man.  He’s got a strong will and a temper.  He’s a doctor and a soldier—the very definition of high-stress careers.  He’s physically and emotionally capable of taking life and death into his hands without hesitation or regret.  He shouts down Sherlock, stares down Mycroft, almost gets the drop on Moriarty, and chews out Detective Inspectors in their own offices.  The only time he ever freaks out is here, when he’s dosed with a fear gas, and even then he manages to keep his wits and think tactically. 

And yet he appears to be completely content to live in Sherlock’s shadow.  He seems to have lost/given up both of his chosen jobs by this point, in favor of working with Sherlock.  Fandom’s already untold bandwidth to analyzing his romantic life in the face of Sherlock.  So he lives with the guy, works with the guy (rather than following his own hard-earned career), dedicates (sacrifices) much of his personal life to the guy, and that’s what’s weird.  

Because John doesn’t really seem like the sort to feed his entire life to somebody that way, does he?  Sure, he’s proven he’s fine with self-sacrifice, but that’s different from self-effacement.  John’s got a strong identity of his own; he obviously doesn’t consider himself insignificant or unworthy of having his own space in life.  He cocks off to government officials standing in Buckingham Palace.  The man’s got confidence.

So I just…my god, he must worship Sherlock, to decide that he’s worth John’s entire life.  But he does, right?  With John, because it’s a TV show, we can only see hints of his internal life through the things he does and says, but with ACD’s Watson, we got the internal dialogue.  And he sees this extraordinary, amazing, unique man, who does what no one else can do.  The kind of person who comes along maybe once in a generation and has the sort of force that can change the course of history.  And I think John thinks, “If there is anything I can do to help him be everything he has the capacity to be, then I’ve left my mark.  I’ve served the world.  He’s worth everything I can give him.”

This is why Reichenbach kills me.  It’s not that it’s the end of John’s life.  It’s more like he’s just seen MLK assassinated in front of him.