On American Idol tonight, Simon used the expression "chalk and cheese"? What does it mean? A British thing?

Question

Sometimes that man is a total puzzlement.

Answer 1

As different as chalk and cheese is an old proverbial phrase to suggest that two things, superficially alike, are totally different in their qualities. There’s nothing in its history to suggest these two counties had anything to do with it — it sounds like yet another folk etymology to me.

The earliest example — from John Gower’s Confessio Amantis of 1393 — suggests that some shopkeeper was making an illicit profit by adulterating his wares: “And thus ful ofte chalk for cheese he changeth with ful littel cost”. The buyer was surely undiscerning; though some British cheeses are rather chalk-like in appearance, substituting more than a tiny proportion of cheese with chalk wouldn’t fool anybody for very long.

By the sixteenth century, the phrase had become a fixed expression. Hugh Latimer wrote rather sarcastically around 1555: “As though I could not discern cheese from chalk.”

Answer 2

The British are far more clever than Americans on the average. It's their education, as how else would such a small nation have ruled the world? Even much of America is what it is because of the British.
Chalk and cheese. Gee...what can it mean? Hint: They both can look the same but have totally different purposes. Incidently the "chalk" referred to does not mean it is in the shape of a chalk used for a blackboard.

Answer 3

Better still ... he said "LITERALLY" chalk and cheese ...

I'm still trying to figure that one out ...