This is probably pretty common, but I used to believe that on your birthday you grew taller.
I remember when I turned five I tried to measure myself, because older kids looked bigger, so now I was five, I must be bigger. My dad laughed and told me it wasn't true and I got upset.
A childhood belief about birthdays

others believed things like this
- I used to believe that everybody who was bigger or taller than I was always older than me.— Stano Finji
- iwas told that if u cry on your birthday you would not get any bigger 4 a whole year— steve
- That 1/4 was bigger than 1/2Anon
- I used to believe that the bigger the coin was, the more it was worth.— Benjamin
- i used to think nickel were work more than dime cause they were biggerAnon
- my dad used to tell me that nickles were worth more then a dime cause they were bigger — brittany