When I was around 6 or 7, I heard about koalas for the first time. I remember thinking they were some brand new discovery/invention or something. i believed this for several years..
A childhood belief about general

others believed things like this
- Before the invention of the camera, everything looked like a cartoon with the quality/effect of oil painting.— MD Caruso
- I remember thinking that non-English speakers were much smarter because they could speak "so much faster." Anon
- I used to think that testosterone was a brand of motor oil.— Grungi
- I remember thinking that the "Nude Furniture" store was some sort of naughty place. — Texas Rocky
- I used to think that girls' anuses were green. I remember thinking that as late as high school.— Jack
- that DOT was a particularly popular brand of motor cycle helmet.— Gary Watrous