-Mabel and Dipper didn't return to Gravity Falls until the summer they were 15 (they would turn 16 at the end of the summer)
-Divorced parents (HEAVY canon evidence behind this)
-Mabel is an L.I.D (lesbian in denial/distress)
-Y'all know that squeaky ass singing/talking voice Dipper had in the show? Yeah, it has evolved into the most angelic fucking voice EVER.
-They didn't drop the journals down the pit, because that decision was just plain fucking stupid.
-Pastel Goth Mabel.
-Some of the boys who bully Dipper took the Journal, and accidentally summoned a demon. Do I have to specify which one, or can you guys figure that out for yourselves? ;)
-Disco Girl doesn't exist. It's just Dancing Queen.
-Stan and Ford were forced to return to Gravity Falls after a boating accident.

YOU ARE READING
Gravity Falls Schist That Lives Rent-Free In My Head
FanfictionTitle is quite descriptive.