I used to think that babies could communicate with eachother, just as adults communicate with eachother. I just assumed there was "baby's English" and then "adult English". I also theorized that if you were at JUST the right age, (for example: 3 year, 7 months and two days old) you would be able to speak both languages.
At the time, I had a cousin who was 3 years old and her brother was just a baby. Me and my cousins all believed in my theory. We sought to exploit my 3-year old cousin and create a "baby translation company". :)
A childhood belief about speaking

others believed things like this
- That because Gerber Baby Food had a baby on it real babies were put in there. Thanks a lot cousin!— Nicole
- I used to think everyone in the world knew and thought in English, but choose to speak different languages. Anon
- At the age of four I believed I was soooo smart. I spoke TWO languages...English AND American!— Melinda
- I only found out last year that a pony is not a baby horse.— Mescaline Frumblethond
- i used to think that every family had a brother and sister and they married eachother when they got olderAnon
- My 5-year old cousin used to believe the garbagemen were stealing their trash.Anon