I used to believe that "luft" was German for red, because of that song "99 Luftballons" being translated as "99 Red Balloons". I also believed that "rico" was Spanish for rice, so Puerto Rico was "Port of Rice" to me.
A childhood belief about foreign languages

others believed things like this
- my brother told me rice crispies were really fish eggs we gave to the goldfish. I never ate rice crispies.— johnboy
- I used to believe the Metallica song "Trapped Under Ice" said "I turned down the rice."— Erik Z.
- My Nan used to say that if you ate rice pudding every day you would live till 100.— Jayne
- Someone told my that rice was really spider eggs. I still don't look at it the same. Anon
- I used to believe that if you ate rice and water and jumped up and down you would explode. Thanks Dad.— Nina
- I thought rice was just another way to prepare a potato, like mashed or fries.— Me