The entire structure of mathematics precariously balanced on a few wooden poles labeled "ZFC." That's literally how it works, folks. Mathematicians built this elaborate skyscraper of theorems and proofs, and the whole thing rests on Zermelo-Fraenkel with Choice—a set of axioms we just... decided to accept. It's like watching a trillion-dollar mansion supported by IKEA furniture. The Axiom of Choice is particularly sketchy—it basically says "trust me bro, you can make infinitely many choices at once." And yet without it, half of modern math collapses faster than that building. Next time someone tells you math is the language of absolute truth, show them this architectural masterpiece.