Arya Stark, Sandor Clegane, and the roles we play
A large part of Arya’s arc is learning how to play a role.
When we first meet her, she’s unable to do this. Societal expectations of femininity don’t come easily to her, and she struggles to perform them. This marks her as a bit of a problem child, which causes friction between her and her mother, who did learn to play this role at a very young age.
However, when Arya is forced to rely on her wits to survive (i.e., when playing a role is truly important), we see her begin learning to play the ever-changing roles required of her. This starts when she plays a meek servant in Harenhall, which primes her for the HOBAW, where effectively playing different roles in the name of spycraft and discreet assassination is essential to the work of the Faceless Men. It’s here where she starts to really hone the craft of slipping on different personas as the situation demands.
Armed with these skills, the Arya who eventually leaves the HOBAW will be far better equipped to achieve social success in Westeros. She may never be great at feminine handiwork, but she will be able to switch between being her authentic self and playing the role the situation demands with fluid ease, as her father did whenever he was required to slip on his “Lord’s face” over the warm, loving, introverted family man we know he truly was.
In this way, Arya’s journey is the exact opposite of Sandor Clegane’s. Sandor has spent the majority of his life suppressing his authentic self to play the role of the Hound. We learn through Sandor’s interactions with the Stark sisters that “the Hound” is largely a defense mechanism adopted by a deeply sad, disillusioned man who has learned from a young age that the society he lives in often rewards cruelty, exemplified by the social successes of his viciously sadistic brother, Gregor.
Sandor is profoundly troubled by this aspect of the world he lives in, and to protect himself he adopts the character of the Hound, who can thrive in such a world. But it’s important to note that while this role does assist Sandor in his society, it doesn’t make him happy. The Sandor we get to know is actually pretty miserable with his lot in life: he hates his job, he’s constantly self-medicating with alcohol, and he doesn’t seem to have anyone he can be his authentic self around.
This starts to change when Sansa Stark comes into his life. After Sandor drunkenly reveals what is essentially the Hound’s origin story, she shows him genuine sympathy and kindness, becoming the closest thing he has to a friend. After spending so long playing the Hound, however, Sandor doesn’t really know how to connect to someone on a real emotional level, and he expresses his feelings of friendship in the most unproductive way possible: trying to “help” Sansa by encouraging her to become as bitter and jaded as he is.
But Sansa refuses to play along. Instead, she continually challenges the cynical worldview that led him to create the Hound in the first place and, importantly, tells him to his face how detrimental this hateful persona is to forming real connections with those who would seek to befriend him if he gave them a chance. Without this pushback from someone who cares about him, it’s quite likely that Sandor would never have found the strength to be anything but “Joffrey’s dog.”
The Hound is a hard role to cast off, but we see Sandor beginning to do just that. If he is indeed the gravedigger on the Quiet Isle, then the next time we see Sandor, it may be the first time we see him as his authentic self.
TL;DR: Arya’s journey is learning to play a role, while Sandor’s journey is learning to be himself