1) Phrase: Cut the Cheese
Origin: Cheese had a thick layer of wax on it's exterior when it was packed. It was bought in large amounts and as it got older and smellier, no one could smell it because of the layer of wax. Once someone cut through the layer to get to the cheese, it released a stinky odor. So when someone smelled a bad odor, they would ask, "Who cut the cheese?"
Meaning: To fart
Original Thought: As a kid I thought it meant somebody had body odor. I thought asking “Who cut the cheese?” was another way of asking “Who hasn’t taken a shower in a week?”
2) Phrase: Throw a Wrench in the Works
Origin: Low paid factory workers used to throw monkey wrenches into the industrial machines to get a break. The phrase was first used in 1931 by The Daily Express - talking about the head of the liberal party - "He hurled a monkey wrench into the machinery of Liberalism".
Meaning: To do something that prevents a plan or activity from succeedingOriginal Thought: I thought it meant to give someone a hand. Like your hand represented a wrench and the works were what that person needed help with.