alt Hacker NewsNo, doesn't mean that either.
People would sell piglets and would try to sell "a pig in a poke" (where a poke is a bag).
That's why you don't buy a pig in a poke because you can't see what you're buying.
Letting the cat out of the bag is because you've revealed that it was a cat rather than a piglet. You've revealed the deception.
Thanks for the correction. In my own words, to commit to memory: once "the cat is out of the bag", the point is not that it's difficult to put the cat back in, the point is that we now know it's a cat and putting it back is not relevant.