(I was monitoring the customers at the self-checkout machines when a customer holding a cilantro angrily waved me over.)

Me: “Sir, what seems to be the problem?”

Customer: “These machines are so useless! They don’t even have cilantro under the look-up list!”

Me: “Sir, it’s because you’re looking under ‘S’ instead of ‘C’ – cilantro is spelled with a ‘C’.”

Customer: “Oh, so you’re a know-it-all, huh? We’ll see what you know when these machines take over YOUR job one day!”

Me: “…”