Common sense is a infinite stream of associated thoughts collected from the MIT's brilliant ConceptNet.

ConceptNet is a semantic network containing lots of things computers should know about the world, especially when understanding text written by people.

It is built from nodes representing words or short phrases of natural language, and labeled relationships between them. (We call the nodes "concepts" for tradition, but they'd be better known as "terms".) These are the kinds of relationships computers need to know to search for information better, answer questions, and understand people's goals.