IMHO, we are all have some genetic transferred common knowledge that are sufficient for our survival. For example, all newborn babies know that they need to get milk from their mothers. We are also born we the desire of owning things and defending our rights. On the other hand, the majority of the other skills are transferred, and earned through real life exposure.
Parents, family environment and interaction, participation and observation with daily happenings are the main source for acquiring common knowledge as I observed.