I used to believe that "priceless" meant the same thing as "worthless". I was quite confused when a TV show mentioned that the fossils in a museum were priceless. Surely, those fossils must be worth SOMETHING...
A childhood belief about speaking

others believed things like this
- I used to believe that priceless meant free.— Neo
- I used to think that "priceless" meant free.— DAAA
- I used to believe that "sue" meant murder, so in movies when someone is getting sued I got really confused— I don't know
- I used to believe that the bigger the coin was, the more it was worth.— Benjamin
- my dad used to tell me that nickles were worth more then a dime cause they were bigger — brittany
- A friend of mine seemed to think that 100 pence was worth £6.— Richard Davies