STAN’S BROTHER IS THE AUTHOR OF THE JOURNALS, AND HERE IS WHY:
So we first saw Stan’s brother (name unknown) in “The Time Traveler’s Pig”, though at the time most people assumed it was a younger Grunkle Stan. But as the series progressed, fans began to notice the differences between the two men in Grunkle Stan’s flashbacks, the most important being the frames of their glasses. So here was the logical theory: Stan has a brother, or some kind of relative. This was further proven in “Dreamscapers”, when one of Stan’s flashbacks revealed a kid, who looks very similar to young Stan, reading a book covering his face on the side. Okay, so this kid grew up to be the man shown in “The Time Traveler’s Pig”. Still don’t believe me? Remember that abandoned room in “Carpet Diem”? When Stan first walks into the room, he notices a pair of glasses sitting on a table and immediately shoves them into his vest, and he is later shown staring at them. Notice the exact similarity between the glasses Stan grabs and the glasses on the man in “The Time Traveler’s Pig”. Weird right? Now listen to this. In “Carpet Diem”, the carpet in the abandoned room has a tag on it that says “Experiment #78”. Where have we seen something similar to this recently? Oh yeah. In “Into the Bunker”, Wendy, Soos, Dipper and Mabel are chased by “Experiment #210: The Shapeshifter”. How could get it get any weirder?? Look at the calendar with the owl. There’s a date circled on it: July 4th. Now any American knows that this is the Fourth of July, and Gravity Falls is in Oregon, so the date is probably just a reminder, right? Or is it something more? Notice the year on the calendar: 1982. Now look at the map in the author’s bunker (shown in the picture with Dipper and Soos). The date on the bottom right-hand corner of the map? 1982. So something big happened in 1982, as that was the year both the room AND the bunker were abandoned. Hmm, when was 1982, like 30 years ago? Wait a minute. Haven’t we heard that before? That’s right. In “Scaryoke”, when Stan pulls the lever for what looks like some sort of portal, he says “30 long years and it’s all led up to this”. Agent Powers, who seems to be keeping a watch over Gravity Falls, notices the reactions and says “We haven’t seen readings like this in 30 years”. The Shape Shifter even tells Dipper, “You’ll never find the author! That six-fingered nerd hasn’t been himself in 30 years.” Oh wait, that’s right, the author has to have six fingers, so it can’t be Stan’s brother. But hold on, we never actually see his hands! Is it all adding up?? Think about it, and thank you for reading!
I think that he was just involved with the author, not that he actually wrote the books. On the wheel in 2, someone expresses surprise at the glasses, but not the hand.
If he wrote the books, why not be surprised at the hand as well? Wouldn’t that be more significant?