My parents divorced when I was a baby. When I was 3 they tried to get back together, the result being my sister.
Up until I was about 10, and had already had some sex-ed in school, I thought my sister was a residual pregnancy from my parents marriage. Then one day my mother pointed out to me that that is impossible, and confessed they had been "trying to make it work" when I was 3....
A childhood belief about family

others believed things like this
- First I believed that my parents were brother and sister. Then I thought that my dad was also my mums dad. — Rainbow
- I used to believe my parents were brother and sister, and that everybody's parents were brother and sister.— Rachael
- When I was little my parents used to tell me and my sister that carrots were "orange candy." — Nancy
- I used to believe that my parents and sister were alligators underneith there zip on human costume...haha— Alyssa
- My sister thought that "Ice, Ice Baby" by Vanilla Ice was actually "US Navy".Anon
- I thought it was impossible for anyone to lift more than their own body weight. Just seemed to make sense..— Xenomorph