Santa Claus does not exist. He is made up for commercial purposes.
911 was missiles and bombs and actors. Some of it all too obvious.
The Ghost who walks is a fictional character by Lee Falk.
Roswell incident was not weather balloons, which the witnesses that lived long admitted themselves.
Earth is not flat like a map, but is shaped like a Globe.
Could probably come up with more.
Maybe you wouldn't count all as conspiracy theories, but some people believe in them.
Also maybe Batman.
911 was missiles and bombs and actors. Some of it all too obvious.
The Ghost who walks is a fictional character by Lee Falk.
Roswell incident was not weather balloons, which the witnesses that lived long admitted themselves.
Earth is not flat like a map, but is shaped like a Globe.
Could probably come up with more.
Maybe you wouldn't count all as conspiracy theories, but some people believe in them.
Also maybe Batman.