something that ive found myself thinking about a lot recently is the loss of autonomy that you have over your identity and what makes you "human" when you die.
(as has been said before by multiple different people) technically ford does not die when he goes through the portal, but as many have said at this point--in a metaphysical way when he goes through the portal he is dead in the eyes of his dimension, so i find in the narrative he experiences a similar loss of his humanity and in the same way that might've occurred with his death, his memory for any that have access to any form of it constructs him into an idea rather than a person.
and really anything can be said and done with him by the people who are still "alive" when this occurs. since he is in all aspects dead people can use him to justify their actions, as a figure in their concepts, and imagine him up to be whoever they want him to be for as long as he remains dead. the audience of course also partook in these same things prior to his reveal by theorizing about what type of person he was or how he might fit into the narrative as a person but to be more specific to examples of this idea in the show is how stan and dipper see ford as an idea.
due to being absent ford had no possible way to influence what stan thought he would want him to do about the portal outside of his existing warnings in his journals so stan is able to twist ford into a justification to work towards opening the portal, and during the length of his work on it according to alex's statements about stan "expecting ford to be weak and in need of help when he came out of the portal" (i feel the likely useless need to say whatever a creator says about their work is always only as canon as one wants it to be but this is worth mentioning here and i think it makes sense contextually within the text) the ford who comes back is so jarring because in his "death" he's become an ideal of what stan wants to see in him to play into his hero fantasy and hopes of earning back his appreciation
and of course as i think about a normal amount of times per day--the duration of the show presents the author as a figure that is wrapped up in a concept of ford while presenting him in a much more mythical format--another one of gravity falls' mysteries. pretty much every main character that isnt stan views him in this mystical light throughout the show with dipper being the prime example and uses the idea of "the author" as a driving force to pursue the questions that the town begs them to ask. there is something to be said about how creators of the show refer to journal 3 as "its own character" in a way that clearly separates it from it's author. even outside of the universe of the show itself, even in the show's own writing team ford--somehow despite being already being only a concept by virtue of being fictional--is stripped of humanity and becomes an even further abstracted concept.
but even to the ford who is alive the self who had gone through the portal is also a concept. i know this idea isnt explored much in canon if at all but bear with me here while i make shit up for fun--in a way, we ourselves the way we are now are dying near constantly. when we wake up each morning we of course have access to the same memories and the same body and the same experiences as the self we were before we fell asleep, but if we were to get existential, how can we be sure that we are the same consciousness that we were before?
even if this is a bit too absurd of a concept to be applying to a messy braindump "analysis" of a fictional character theres something about how extreme change in a person (often from trauma as ford has experienced for Obvious reasons) or even just the passage of time leaves the former self as nothing more but a memory to even the body that it once inhabited.
as i said theres not much to connect this to in the canon of the text, but i do believe that ford does see his past self who wrote the journals as an idea just as much as anyone else in his life did.
