Until about 1982, when I was 12, I thought that Feminism had fixed everything so that there was no more sexism. I was assured by my parents that it didn't matter that I was a girl, I could do anything, because the world was feminist now.
And then when the Equal Rights Amendment didn't pass, imagine my surprise and horror. And then gradually getting to see and experience painful sexism especially after puberty! Moving to Texas sure didn't help.
I also thought some vague hippielike partner to "Feminism", which took place in "The 60s" had fixed racism as well. I don't think I ever heard of the actual civil rights movement until I was at least 12 or 13. Nor did I know of any other feminist movements until maybe late high school.
A childhood belief about politics

others believed things like this
- i didn't beleive this, but a kid my sister knew thought if he screamed in a really high voice, he ran faster.Anon
- I used to think that girls' anuses were green. I remember thinking that as late as high school.— Jack
- I thought I was the only person in the world who didn't like ice cream— Bootlebat
- I thought you didn't have to go to school when it was your birthday.— M_1
- I grew up in NY and used to believe that The Dukes Of Hazard took place during the Civil War.Anon
- I didn't quite grasp the concept of time zones, and thought that Chinese kids went to school at night.— Giselle