I've read a lot beliefs to do with 'salt and pepper cancelling each other out', well, I had a similar one.
Aged about....4 or 5....I had the belief that salt and sugar cancelled each other out, as a sugar lover I would eat some (in handfuls), then eat salt right after (in handfuls) so that they would cancel each other out and (technically) I wouldn't have eaten anything.
It took me several months to devise the 'ingenious' idea of eating the salt FIRST so that it's nasty taste would be taken away by the sugar. It took many more years for me to realise that my idea was wrong. I was a dumb kid (I once tried to make peanut butter by chewing up a handful of peanuts and some butter- that's how they make it, right?).
A childhood belief about salt

others believed things like this
- When I was a little kid I thought that salt was some form of an aged sugar.— Jodie
- Salt is bad tasting sugar.— cobra
- Salt is sugar from a different country.— Santa Puncher
- I thought that veruca salt was green salt— Ninny
- I used to think that salt grew on salt trees.Anon
- I used to think that pepper was only used to mark where you'd put the salt.— BK