I used to believe that Grandparents were assigned to their grandchildren. When I was four I used to ask my mom if her mom died and she would say "No, Grandma is my mom." I had to ask her a few times before I finally remembered it though.
A childhood belief about family

others believed things like this
- I used to believe that My grandparents didn't have any other name except grandma and grandpa.— Emelia
- I used to think my grandparents were born in prehistoric times.Anon
- My birthday was on a different day every year, assigned by my parentsAnon
- I used to think that "One, two, three times a lady"
was: "one, two, three times related"Anon - I thought there was some video games so hard that if you died on them you also died in real life!— Kakuri
- When I was little I believed when an actor died in a movie, he died in real life.— Ben