When people want you to keep a secret they often say, “Keep it under your hat.”
This strikes me as odd because that saying comes from years gone by when archers used to keep a spare string for their bows under their hats, where the string would, hopefully, remain dry.
I don’t see what’s secret about this. Perhaps it’s just how language is shaped by a sort of ‘Chinese Whisper’
Sometimes people say they’ll keep their lips sealed when they ‘intend to keep a secret.’ Why should we trust anybody who says that? They could always use a paper and pen for their act of betrayal.
Then we’ve got the old saying:
Cross my heart
Hope to die
Stick a needle in my eye
Frankly, if somebody we’re threatening to stick a needle in my eye I think I’d probably tell all.
But then I’m pretty selfish.
Actually, I remember telling a friend at school, Neil his name was, that I fancied a girl called Andrea, and asked him not to tell anyone.
Needless to say, the next day every pupil and teacher in school knew, including Andrea.
“I told you not to tell anyone,” I protested
“I didn’t tell anyone,” said Neil. “I only told Gaz and he isn’t anyone.”
Which is probably why I’m pedantic now.
Just Language 