- Stan's short speech about life and death in the "Trooth Ache" segment from "Bottomless Pit!", becomes even more depressing after the reveal of his rough backstory in "A Tale of Two Stans".
- In "The Legend of the Gobblewonker" Stan trying to bond with the kids because he feels like a lonely and abandoned old man becomes a lot more poignant when it's revealed that he was disowned by a majority of the Pines family and later lost his own twin.
- From the same episode, the name of Stan's boat (the Stan-O'-War) is a lot more heartbreaking after we see that he and his brother owned another boat by the same name together before their falling out.
- In Dreamscraperers, Dipper overhears Stan saying how "he's a loser, he's weak, I just want to get rid of him." Dipper's extremely hurt, but when he finds and views the full memory in Stan's head, he discovers that Stan was actually comparing Dipper to how he himself was as a child. Then we find out Stan was cast out of his family in A Tale of Two Stans.
- Stan justifies his tough treatment of Dipper by showing that his dad treated him similarly, which taught him to be strong and fight back. But "Not What He Seems" flashes a book called Daddy Issues on his book shelf, and "A Tale of Two Stans" shows that Stan's father Filbrick's rough treatment went beyond just simple "encouragement to be strong", both implying that the way Filbrick treated his sons actually emotionally scarred at least Stanley if not both Stan twins. Knowing this, Stan's calm decision to treat Dipper similar to how his father treated him, even if Stan is just making Dipper do a lot more (admittedly unsafe and grueling) chores, gets a lot more messed up and really makes you wonder what the heck is going on with Stan psychologically.
- Remember how irritable Stan was over the hidden room, and how he spent a lot of the episode moping while looking at a pair of glasses? It's revealed in A Tale of Two Stans that he spent close to a month in that room in a Heroic BSoD, and the glasses are his brother's. He was remembering how he accidentally threw his brother into Another Dimension.
- Remember when Stan said to Dipper and Mabel that it was almost unnatural for them to get along so well? It's revealed that he actually had a great relationship with his own brother, but they spent so long estranged from each other that Stan seems to have forgotten what a healthy sibling relationship is like. Then when he tried to get on friendly terms with his brother, he accidentally started a fight that ended up in him losing his brother for a long time.
- Remember when Stan told a light-hearted story about Waddles becoming sentient, leaving Mabel behind to build an intelligence-enhancing machine with Dipper which insides looks like the portal? And that Waddles eventually gave up his intelligence to restore his bond with Mabel, unlike Ford? It's a retelling of what happened between Stan and his brother, with Stan as Mabel and Ford as Waddles with the ending altered to the one he favored.
- In "Dipper and Mabel Vs. The Future", Ford asks Dipper if being a twin was suffocating for him. Immediately after this episode aired, the game Gravity Falls: Legend of the Gnome Gemulets was released, implying, among other things, that Dipper almost died of asphyxiation at birth, nearly strangled by one of the two umbilical cords in the womb.
- Stan's idea to burn Journal #1 in the flashback of "A Tale of Two Stans" becomes this when Bill ultimately burns the three journals in "Weirdmagedon Part 1".
- In the episode The Legend of the Gobblewonker, Park Ranger McGucket ignores his crazy father Fiddleford "Old Man" McGucket, who makes a big show to the citizens of the town that a lake monster, the Gobblewonker, had destroyed his boat. Nobody but Dipper, Mabel, and Soos believe him. When Dipper finally manages to get a picture of the Gobblewonker, Old Man McGucket reveals that it was just a robot he built to get the attention of his son, who had been ignoring him. This was already sad, but in "Society of the Blind Eye" it was revealed that Fiddleford used to be sane, but slowly went crazy wiping his own memory to un-see terrifying things, which would have happened while his son was only a small child.
- The reveal in "Blendin's Game" that Soos has such Undying Loyalty to Stan because Stan is his Parental Substitute for his Disappeared Dad is sad enough to begin with, but then Soos has had that trust and loyalty shaken by the events of "Not What He Seems". Thankfully it all worked out.
- Louis CK's guest appearance cajoling people to climb into his mouth picked up some very uncomfortable parallels when he admitted to several cases of sexual harassment a couple years later. Alex Hirsch was even driven to re-record the lines himself for reruns.
- Robbie's voice actor T.J. Miller was also accused of sexual assault, which makes Robbie's creepier behavior towards Wendy even harder to watch.
- The fireworks sequence in "Not What He Seems" and the ease with which Stan deflected Blubs' asking for a permit is this for Oregonians after the 2017 Eagle Creek Fire, which was started by fireworks being lit off during a burn ban due to high temperature and extreme fire risk.
Harsher In Hindsight / Gravity Falls