Fellow food-and-word nerds, you're in luck!
If you're anything like this nerd, you'll be majorly fascinated by Smithsonian's helpful compendium of the origins of food idioms, from "red herring" to "salad days." Another list takes on those of foreign languages — many of which lose quite a bit in translation. (I'll never forget the sight of a friend's Bulgarian mother screaming "PEPPER HEAD!" at other motorists.)
Among the most interesting bits of trivia: "spilling the beans" comes from ancient Greek election practices of voting with legumes; a "red herring," meanwhile, threw hunting dogs off a scent. The authors were unable to find the derivation of "go bananas," but it doesn't seem like too much of a stretch to make the connection to monkeys, surely...or at the very least, the other incomprehensible inanity of the 1922 novelty hit "Yes, We Have No Bananas."