#2:
When chicks first hatch, the have a tooth. The tooth falls off, usually within a very short time. It is possible for it not to fall off, and you end up with a hen that has a tooth, but this is extremely rare. So, the saying doesn’t mean something doesn’t exist, it just means the thing is mindbogglingly rare.
thankas i always wondered about that
An oral agreement isn’t worth the paper it’s written on.
An oral agreement isn’t written on any paper, so it’s worth less than nothing.
I’ll pay you on the Greek Kalends.
The Greeks didn’t observe Kalends, so this means I will never pay you.