In this latest round of Jimmy Fallon's "Late Night Hashtags," the host asked people to tweet the things they used to think were true.
You know, like when you were a kid and used to pretend that the floor was lava. Or when you were an adult and thought Ellen's last name was The Generous.
Using the Twitter hashtag #IUsedToThink, the game became a trending topic in the U.S. in under 30 minutes, so you know there were some good ones. Watch the video above to hear Fallon read his favorites.