If Sherlock Holmes is the ultimate detective, then Watson is the ultimate sidekick. He's just sort of there most of the time. Part of the problem with understanding Watson is that he's our first-person narrator. It seems like this would give us a lot of insight into Watson, and it might if Watson were talking about himself. But he's talking all about Sherlock Holmes, so half the time there is no mention of Watson's dialogue or actions. He pretty much keeps the spotlight firmly on Holmes. So what exactly does Watson do on all these cases, aside from follow Holmes around and record things for posterity? Does Watson really exist outside of Holmes? To answer that, we'll need to check out what Watson actually does in these stories.
Watson conveniently tells us himself what his agenda is at the start of a few of the stories here.
I confess that it is very difficult for me, out of such a wealth of material, to select the cases which are most interesting in themselves, and at the same time most conductive to a display of those peculiar powers for which my friend was famous. (Pince-Nez.1)
Watson is a sort of historian who is "selecting" interesting cases, that show Holmes in a positive light, to share with people. He's like a self-appointed biographer/historian of the great Sherlock Holmes, with some eyewitness reporter thrown in for good measure. As the narrator of events, Watson is necessarily a bit of a bystander.
But there is also a lot of power in being the narrator. Watson is in charge of which cases get told and how they get told. Every character in these stories is subject to the narrative and editing power of Watson the storyteller.
[B]ut by degrees, with many repetitions and obscurities which I may omit from his narrative, he laid his strange story before us. (Three-Quarter.19)
Watson is basically in charge of everyone's stories here, and it's a responsibility he takes seriously. In fact, the entire historical legacy of Sherlock Holmes is in Watson's keeping. Holmes may have the power to solve crime and do exciting things, but Watson's power is no less important. Watson has the power to influence how people think about Holmes and how they understand him and his work. He also has the power to make people think of Holmes at all; Watson decided to write these stories in the first place, ensuring that Holmes would actually have a popular historical legacy.
So as the Holmes historical expert, Watson is also necessarily a memoirist, a public relations agent, a biographer, a researcher, an editor, and a storyteller. He's got a lot going on there, which makes his wallflower routine in most of the stories somewhat confusing. We'll get back to Watson's background extra thing later. First though, let's check out some of the things that Watson's narratives reveal.
All right, so we've established that Watson is pretty important, all appearances to the contrary. Other than his bromance with Holmes, though, what do his narratives tell us? Well, Watson's writing actually indirectly reveals a lot about who this president of the Sherlock Holmes fan club really is. Turns out, Watson really does exist independently of Holmes, though you sometimes have to squint to see it.
First off, even though Watson makes a career out of following Holmes around, and following Holmes's lead on most things, he is very different in terms of thoughts and personality. A quote from Holmes helps to shed some light on this:
"I must admit, Watson, that you have some power of selection, which atones for much which I deplore in your narratives. Your fatal habit of looking at everything from the point of view of a story instead of as a scientific exercise has ruined what might have been an instructive [...] series [....]" (Abbey Grange. 6)
Watson may try to mimic Holmes's crime solving skills, as we see at the start of the "Empty House." But he also pursues his own activities (writing), and he does so in a way that Holmes doesn't really like. Watson is definitely not a Holmesian scientist/detective. Rather, he's a romantic living with and interpreting a scientist.
Watson's romantic streak comes through a lot, especially when he's describing a woman. He's a bit of a ladies' man, which definitely contrasts to Holmes. Watson can get downright schmaltzy at times when he's describing women. Here's a sample from the "Golden Pince-Nez":
[F]or she had the exact physical characteristics which Holmes had divined, with, in addition, a long and obstinate chin. [...] And yet, in spite of these disadvantages, there was a certain nobility in the woman's bearing – a gallantry in the defiant chin and in the upraised head, which compelled something of respect and admiration. (Pince-Nez.151)
Holmes and Watson have very different worldviews. Holmes sees suspects and motives when he looks at people. In the above passage, Holmes determined what the suspect looked like because the fact that she wore glasses was significant in the case. Watson, meanwhile, takes time to comment on this woman's "noble bearing." Watson sees a bigger picture than Holmes, who is often concerned with scientific minutia, or small details. Instead, Watson sees human personalities and emotions when he examines people.
The fact that Watson takes time in his narratives to comment on personalities and emotions says a lot about who Watson is as a person. Watson's frequent use of metaphors also hint at his romantic nature. (Check out the "Style," "Tone," and "Narrative Point of View" sections for more on Watson as a narrator.) In a lot of ways, Watson is the normal counterpart to the antisocial Holmes. Yet Watson chooses to live, work, and basically devote his life to an oddball. What's the deal here? Well, it's the time you've all been waiting for: we get to check out the bromance.
Watson is the ultimate Holmes fanboy. And it's this hero-worship mixed with bromantic love that explains why Watson is so willing to hang around Holmes and put up with all his irritating quirks. He's oddly dependent on Holmes, just as Holmes is oddly dependent on him. The bromance isn't one-sided here. These two dudes live and work together, and they can't seem to get along very well without one another. Holmes needs Watson to be his wingman, provide back-up/moral support, and applaud him. Watson's needs are a bit simpler to determine: Watson needs Holmes to provide him with some excitement. The eccentric Holmes is a way for the normal Watson to avoid having a boring life:
I found myself seated beside him in a hansom, my revolver in my pocket, and the thrill of adventure in my heart. (Empty House.36)
Watson is a bit of an adrenaline junkie, and he has fun tagging along with Holmes on exciting cases. It seems like Watson badly needs Holmes and, given the way these stories are narrated, it seems like Watson pretty much blots himself out in service to Holmes. The fact that Watson focuses his narratives so much on Holmes is telling.
But Watson isn't totally dependent on Holmes, nor is he totally blind to Holmes's faults. The fact that Watson is narrating these stories at all, and the fact that he narrates them as romantic fiction rather than a science textbook, shows an independent streak. Watson also doesn't just spend all his time carrying on about how awesome Holmes is. He mentions Holmes's faults, his difficult personality, his past drug addiction, and even includes scenes where Holmes makes him angry.
And this "inclusion" of certain scenes brings us to the most intriguing aspect of Watson's character. While he may not be spotlighted in these stories a ton, these thirteen stories essentially are Watson. Every case, every scene, every bit of dialogue, and every phrase shed light on Watson since he chose them. Watson may spend most of his time talking about other people, but the way in which he speaks about them give us a huge amount of insight into who Watson is, and into his complicated relationship with Sherlock Holmes.