@SmudgeTheInsultCat @DaywalkingRedhead Pluto is the 9th planet (obvs.)

But my favorite is:
The earth’s crust rests on an unbroken sphere of molten lava. Volcanoes erupt when this lava somehow becomes disturbed or overheated. Continents are right where they always have been. (Plate tectonics came in about 20-30 years before I graduated high school, but my textbooks hadn’t caught up.)