My younger brother used to believe that he was older than me 'cos his birthday was in March and mine was in December.
A childhood belief about birthdays

you weren't the only one
26 of you believed this
- I used to believe that I was older than my brother because I was born in June and he was born in OctoberAnon
- i used to think that i was older than my dad because my birthday was before his— zara
- My cousic used to think he was older than me because his birthday was in June and mine was in December.— //**...Ethan...**\\