Also…the ending of Gravity Falls is satisfying purely because it satisfies the emotional arcs it sets up with its characters.
Because I hate to say this but…if the ending were judged purely on how well it wrapped things up from a plot point of view it’s…actually…not…great?
I mean the memory gun and the metal plate in Ford’s head both suffer from a huge case of “it does whatever the writers tell it to do to fit this specific need in this moment.”
Mabel’s prison bubble is, in a physical sense, fairly easily escaped–Mabel just pops it with a huge pin.
And people have pointed out that by bringing Stan’s memories back, the writers created an heroic sacrifice, and then took away the sacrifice part.
The technology in GF working in a maybe somewhat contrived way sets up a circumstance through which Ford and Stan can mend their bridges. Stan volunteering to have his mind erased is the culmination of all the build up surrounding Stan’s low self worth and his desire to prove himself as a hero.
It also satisfies an arc with Ford, by allowing him to appreciate his brother for the first time, and to understand that his concept of what a hero is was faulty all along. This is what prepares Ford for the happy ending he eventually receives. It also answers the question brought up in AToTS–will Ford and Stan ever resolve their differences?
Mabel’s bubble is escaped quickly when she is ready to escape it. When she wants to face reality and finds the strength within herself to pierce the fantasy. It’s the resolution of her “fear of growing up” arc that had been with us from the beginning and intensely emphasized since the end of AtoTS. It reaffirms the themes of “growing old is mandatory, growing up is optional” and “life is less scary when the people you love are facing it with you” that have been with us from the start. It prepares her and Dipper for the hopeful “let’s grow up together” ending they get.
It also answers the concern brought up in AtoTS and enormously emphasized in DaMvtF–will Dipper and Mabel be split apart? There’s development for Dipper as well–he puts his trust in Mabel, deciding he’d rather grow up with her and face the world together than take on the implied isolation of Ford’s apprenticeship.
Stan getting his memory back might ultimately mean he does not lose anything. And if the point of that ending was for him to give something up, that would probably be disappointing. But it wasn’t–as mentioned, the purpose of Stan’s self-sacrifice was to create a climax for character arcs surrounding himself and Ford. Stan’s already given up plenty.
Mabel bringing Stan’s memories back with her scrapbook, besides being an emotional moment, ties into all the show’s themes surrounding family, loyalty and love. It brings back an object we’ve seen in the background of the show since the very beginning, one that was never emphasized as important, and uses it to save the day. It’s the zenith of Stan’s relationship with both the twins (seen through his relationship with Mabel,) which has developed over the course of the summer from something distant and awkward to something beautiful. And it ties into Mabel’s own arc–she just escaped a supernatural prison bubble through the help and support of her brother, and now she can give that same support to Stan.
These are the important things. These are the arcs that need resolution. With that in mind, it doesn’t really matter that the metal plate in Ford’s head and how it relates to Bill entering his mind makes no flipping sense at all.
(Because wow it makes no flipping sense at all and I don’t even care the slightest.)