When I was young I had heard many times the expression "Naked as a jay bird" and knew what it referred to, but later I heard someone mention something about 'jay walking' and I thought it meant someone was walking around naked.
A childhood belief about speaking

others believed things like this
- I used to believe jaywalking meant walking around naked in public (from naked as a JAY bird...)— Izzi
- I used to believe that jay walking was walking naked on the street. — Kendra
- i used to think the song "walking in a winter wonderland" was "walking in a womens underwear"— stephen s
- I used to believe that showing my bare arms meant that I was naked, so I never wore short sleeves as a kid. Anon
- Well I once believed that when someone was home alone, they'd walk around naked..Anon
- I used to think that a strip mall was where you shop naked.— WD