My mom had to leave early for a doctor's appt once during lunch hour, and she told me that I had to leave the house at quarter after 12 in order to get in school on time. I was so proud of my self for figuring out that quarter after 12 means 12:25 since a quarter is 25 cents, so quarter after means 25 after..
A childhood belief about general

you weren't the only one
13 of you believed this