Something about how Joel needs to know a specific purpose to work towards for him to go on... Not that others don't, of course they do, it's the most human thing, but how its just a lot more specific with Joel...
When Sarah was alive, she was his purpose. To raise her, to give her a life, to keep her safe... and after she passed, he didn't have that purpose anymore, so he tried to do what he did the very next day...
We see this with Tess too, and I think another post already pointed this out, how she is very much the leader between the two of them. Tess guided him, she gave him goals to carry through, she gave him purpose. Even when they meet Ellie, he only takes her along because Tess decided to. Hell, he was ready to abandon Ellie after finding out she was infected but didn't because Tess said not to.
We have seen the kind of tunnel vision of greif and rage he goes through when he loses his purpose, we have seen it with Sarah, we have seen it with Ellie, but we do not see it with Tess. This was one of the most important relationships in his life through 20 years of the apocalypse, and sure he mourns her but he's never blinded by it. Why?
Because just before her death, Tess gives him a new purpose, to keep Ellie safe. And that's exactly what he does. Only that, over the course of the episodes, the purpose that came out of obligation turns into genuine parental love.
That's also one of the reasons Joel's search for Ellie this episode is so interestingly shot. I mean, in the last episode when Joel was torturing those two men, everything was loud and crystal clear, every scream, every breath, every movement of the knife. Because Joel woke up and his kid is missing, all her things are missing, and at this point he has no idea where she is or if she's even alive. And so that scene is neither from Joel's pov nor of those two men. The audience is literally a third observer watching this guy torture the fuck out of two others. The scene from the last episode is the complete opposite. Especially for what is one of the most violent scenes in the show, I mean Joel kills a building full of people in cold blood. But we hear no sound, everything is muted, most of the camera's attention is either on Joel or his boots, not the bloodshed in front of him. This is the one scene we get to see that is completely from Joel's point of view, from the moment he takes the gun in the staircase till he reaches the operating room, we see that blinded tunnel vision that Joel has. He has one purpose - to find Ellie. Anything else doesn't matter, and so he doesn't even register all the things he's doing, all the people he's killing.
And then he sees Ellie, and the audio returns to normal, the camera pans out. When he shoots the surgeon, it is loud, it is clear. It is personal. And he could have killed the nurses, dragged Ellie away from the bed himself and be done with it. But no, he asks the nurses to remove all the wires off of her, and to bandage up her arm, and he puts her in the car before he kills Marlene, not after. Because he completed his purpose of finding Ellie. His new purpose now is to keep her safe from anything that could hurt her, whether its seeing someone die or a single drop of blood on her arm.
Joel's arc, from the first episode till the last, is having his purpose as a father break apart and then having it glued back together, piece by piece, all by the drive he has to protect his little girl
And god help any motherfucker who stands in his way























