My parents have the same birthday (but my father is a year older than my mother), so I automatically assumed that ALL parents had the same birthday. When we went to a neighbors house for their birthday, I couldn't understand why it was only one person's birthday, and not both. It took me a good two hours to realize that most people's parents don't have the same birthday.
A childhood belief about family

others believed things like this
- My parents have the same birthday -- month, day, and year. I though all mom's and dad's had the same birthday.— Cait
- My birthday was on a different day every year, assigned by my parentsAnon
- Up until I was almost 11, I thought that a birthday suit was a special outfit you wore only on your birthdayAnon
- I used to think that your birthday changed every year, and that your parents just decided what day it was.— Daniel
- I used to think that a birthday suit was a special outfit you wear on your birthday— Bri
- I used to believe that on your birthday, you didn't advance to your next age until you ate your birthday cake.— Casi