We all know and love Ygritte's favourite phrase:
You know nothing, Jon Snow
- Ygritte
But, what on Westeros does it mean?? Is there any official word from George R. R. Martin stating what he means by this line?
Even Kit himself doesn't seem to know what it means:
I don't think there's any deeper meaning that just what it says: She's calling him an idiot. She's telling him that he doesn't know or understand nearly as much as he thinks about how the "real world" (her real world, at least) works.
Remember that, when the two met, Jon Snow had lived a relatively sheltered life. He grew up as a not-quite-noble, who was shuffled off to the Wall when he was just a teenager. I think he's supposed to be older on TV, but in the novels, he's 15. Once he gets to the Wall, he takes his vow of abstinence, and proceeds to be a Night's Watchman. That's the sum total of his real-world experience.
Ygritte, on the other hand, is a wildling who's has to survive, seemingly on her own, for many years. We never see any hint of parents, though as she's 18 when we meet her that may not be unusual. More importantly, she has clearly been in relationships before, and has learned how to take care of herself.
During their time together, Jon initially expects her to want to be treated the way the women he knows would, but his only source of comparison would be people like Sansa, or at best Arya. Ygritte is vastly different from them. Jon also exposes all of his prejudices about how the wildlings live, which Ygritte considers stupid. Jon is also clearly still a virgin, and when Ygritte starts flirting with him, his inexperience shows.
Initially, when she tells him he knows nothing, she means exactly that: "You think you know everything about my world, but you know nothing."
Later, after she warms up to him, the same phrase takes on more of a teasing tone. It's an insult, but a playful one, reminding him that she's the one with all the experience.
At least at first, she uses the expression to point out that he knows nothing of what it means to be a wildling. Being a "southerner" growing up in a castle, Jon has never lived with these people, tried to understand their culture, or had to survive off the land. And she enjoys pointing this out on many occasions...
From an in-universe prespective we are offered what Orell thinks of the phrase.
It essentially means that Jon does not know how the world truly works. That even with constructs like team work, loyalty, honor, and even love are temporary things that only used when convenient to both parties.
It is kind of the classic "book smart" versus "street smart". Jon is educated in history, math, reading, writing, and other important things, but when it comes to surviving out in the real world most of that means nothing and when it comes down to only that Jon knows nothing.
[previous discussion on marching, etc.]
[Ygritte] You know nothing, Jon Snow.
[Ygritte walks away and Orell walks up]
[Orell]: She's right, you don't.
[Jon] I know you cut me loose on the wall.
[Orell] I cut her loose too. Do you see her sulking about it? That's because she understands the way things are...
[Jon] And now you're gonna share it with me; the deep wisdom you found inside the head of a bird.
[Orell] People work together when it suits 'em, they're loyal when it suits 'em, love each other when it suits 'em, and they kill each other when it suits 'em. She knows it, you don't. Which is why you'll never hold onto her.
Game of Thrones, S03E07, "The Bear and the Maiden Fair"
IMO it is one of Game of Thrones' many double entendra phrases, in which there is more than one meaning. There is the more intimate exchange between Jon Snow and Ygritte, where she is making him out to be unknowledable.
However, it also expands to an idea that everyone is in some way ignorant, (including Ygriite knows nothing of civility on Jon Snow's side of a the wall) because no one (another important phrase used by Faceless Men) character has all of the answers or all of the power.
You no nothing, Jon Snow = No One Knows Everything. (And maybe the more you think you know, the less you do, because 'everything changes' or there is more than one way to look at or interpret something/ Martin stated for instance, that he will not definitevly expain the true metaphysical nature-how many Gods, is there a God, which God(s), ect)
In addition looking closer at Jon Snow, it's true to some degree that Jon is not the most expirienced and ultimately not extremely knowlegable, but because Game of Thrones/Song of Ice & Fire's universe relies on metaphysics, possibly cycle cosmology, it's clear that none of the characters are fully in control of their own fate and that identities are transformative, fluid, or blurred (often through the use of magic, which is furthered in the books with bigger suggestions of reincarnation as an additional example), therefor there is an element of destiny or predeterminism, and because of Jon's Snow's [mostly] good nature with virtious intent leading the way, one can argue Martin/GOT EPs are making a philsophical point about importance of compassion, over intellegence or expirience.
