When I was little (6 or so), I knew that 'lupus' was a disease, and I also knew that 'lupe' was Latin for wolf; so I assumed - and I think this was a quite reasonable assumption - that perople with lupus were werewolves.
A childhood belief about being ill

others believed things like this
- i used to think that the language pig latin was called pig latin because it was used by pigs— kim
- I used to believe that Latin was spoken in Latin America.— C.C.
- I used to believe that all old people got the disease "OLD TIMERS DISEASE" Instead of alzheimers disease :D— MollyJohnson
- I used to think that Alzheimers disease was called Old Timers Disease.— Justin
- That Alzheimer's Disease was Old Timer's Disease.— Todd K
- When I was a kid, I thought there was a country where they spoke Pig Latin. — keyboardplayer