Right as rain
Meaning: Completely correct, proper, sound and healthy.
Example: On the witness stand she appeared to be right as rain, but then she is an actress by profession.
Origin: This one is likely alliterative. The "R"'s in Right and Rain sound good together.
This comes from the idea of rainwater being pure and wholesome - well it was before pollution.
This may be reference to the value and goodness of rain which is critical to crops and farming.
shrug
Originally posted by GuitarBunny
How about this one?"I don't give a rat's ass!!"
hee hee
I Don't Give A Rat's Ass
It's just general slang that started up sometime during the 20th century. While nobody knows for sure how it came about, it's believed that a rat was used in the expression because of the way people view the rodent (annoying and small).
You Can't Have Your Cake And Eat It, Too
The original version was "you cannot eat your cake and have it too." John Heywood's Proverbs had that version back in 1584, which means that if it was published then, it was around for even longer than that. Incidentally, Heywood published it as "Wolde you bothe eate your cake, and haue your cake?"
shrug