I used to believe that "Baby Got Back" by Sir Mix-a-Lot said "I like big butts in a can..." Always wondered how anyone could get their butt in a can... Then the line "When a girl walks in with a really big bin" helped me make the connection that those "cans" were really trash cans, aka garbage BINS. So I envisioned that Sir Mix-a-Lot liked girls who walked around with trash cans on their butts...
A childhood belief about misheard lyrics

others believed things like this
- I used to believe there were calves' heads in those cans of Pet Milk.— Ron
- For years and years I believed that tuna must be really little fish because they came in such small cans!!— Gisela
- My 5-year old cousin used to believe the garbagemen were stealing their trash.Anon
- My kids believe if they pick their nose their butts will fall off!— wendy
- When I was young I want to grow up yo be a trash man, becuse they only work one day a week.— Steve H
- I used to believe that they got the lunchmeat bologna from cutting off dead people's butts.— angie