One of the most astonishing things about LLMs is that they actually seem to have achieved general common-sense reasoning to a signficant extent. Example from the thread about somebody ordering 18000 waters at a drive-through: https://news.ycombinator.com/item?id=45067653

TL;DR: Even without being explicitly prompted to, a pretty weak LLM "realized" that a thousand glasses of water was an unreasonable order. I'd say that's good enough to call "common sense".

You can try it out yourself! Just pick any AI chatbot, make up situations with varying levels of absurdity, maybe in a roleplay setting (e.g. "You are a fast food restaurant cashier. I am a customer. My order is..."), and test how it responds.