I used to believe that several meant seven. This was because the first time I remember anyone saying it it was grandma, who told me that there were several planes in the sky - coincidentally there happened to be seven and I thought the words menat the same thing.
A childhood belief about counting

others believed things like this
- I used to think you couldn't die if you didn't have shoes on. Coincidentally, so did one of my friends.— Casey
- When I first heard the words "flea market", I actually thought it meant "selling fleas".Anon
- I thought that exorcise and exercise both meant the same thing— Dobby Bob
- I used to think that dreams were events that really happened, I just couldn't remember them when I was awake.— Warren
- I thought the phrase "At one's disposal" meant you should dispose of the person or thing.— Geirskogul
- i believed like when i was 3 yrs. old i thought that air planes would come to your house to pick you up!— Brooke