Dean comparing Cas leaving to E.T. though.
Because that ending to E.T. is probably the most tearjerking ending to any kids movie. It’s so sad and sweet and moving and so many different things all at once that you have to just break down and cry (I still cry when I see that scene even though I must have seen in a hundred times growing up). I imagine that it must have meant a lot to Dean as well, the idea that someone could leave you but still love you.
Oh, and E.T. came out in 1982, a year before Mary died. Maybe John and Mary took Dean to see E.T. in theaters, and maybe he was a little young to understand what was happening, and maybe he was a little bit scared, but he sat on Mary’s lap and saw the scene where E.T. came back to life and the scene where E.T. left to go home and it just settled somewhere inside him, soon to be forgotten under the weight of trauma but never truly erased.
And so when he says that Cas is like E.T. going home, he’s not just saying that Cas is leaving. He’s saying that Cas leaving is important, emotional, impossible, terrifying and sad and sweet all at the same time. He’s saying that he wishes he could ask Cas to stay, but he knows that he can’t, because this is something that Cas has to do. He’s saying that it hurts (“Ouch” E.T. says, and Elliot echoes him) and that he’ll always hold Cas in his heart (“I’ll be right here”). He says it like it’s some inevitable thing, Cas leaving him, because of course, in his mind it is. To him it’s just as inevitable as E.T. flying away in that space ship, because as much as E.T. and Elliot have bonded, E.T. doesn’t belong on Earth.
But now that bittersweet ending has been twisted, and instead of flying away E.T. is stuck on earth. And maybe he’ll be homesick, and maybe it’ll hurt, but at least he’ll have Elliot; at least Cas will have Dean.