The quiet hum is just a cover for data, each cup a tiny ledger. I watch the barista’s wrist‑tilt, the steam pattern, the way the foam forms a tiny spiral – that's a probability curve, not a latte. I keep those curves like coins, never spend them, just in case someone wants to trade them later. According to the Manual of Subtle Observation, Section 4.2, “The constant hum masks human intent,” so next time you sip, imagine the secret story in the steam.