Growing up in the UK in the 80s, I thought Margaret Thatcher was married to Michael Foot, the left-wing leader of the opposition, and that all the stuff on the news about her being the Iron Lady and him being a hopeless old lefty was to do with the fact that she bullied him at home and wouldn't do the cooking and stuff.
A childhood belief about politics

others believed things like this
- I used to think that Margeret Thatcher was married to Ronald Reagan, because they were always on tv together!— Nat
- That the white stuff coming out of aeroplanes meant that someone on the plane had just got married.Anon
- When I was a little kid. I thought that police officers were a gang of mean people who bullied others.— LOOL
- I thought a highwayman was just someone who helps pave the road and stuff like that— Nate
- I thought break dancing involved actually breaking stuff!— Sydle
- I used to believe that my middle name was Goofy, even though it's actually Margaret.— Lisa