For years I used to believe that cat's sucked the breath out of baby's mouths. I believe that's not an uncommon myth.
A childhood belief about cats and dogs

others believed things like this
- i used to think belgium was a myth.Anon
- If you hold your breath and make a wish under a highway tunnel it will come true....I still hold my breath :)— aj
- Do you really mean to tell me that father Christmas is a myth?
Finally......— Peter (Aged 70) - I used to believe that monkeys were related to fish as they both have mouths!— Quako
- i used to believe that babies had no mouths because they couldnt talkAnon
- We put food in our mouths, so naturally I believed my stomach was in my head.— Timb