Commom Sense is Not Common

Why is it called common sense anyway?

A lot of business sense and expertise is common sense. Many excellence programs distill to common sense. ISO 9001 QMS, TPM, 5S, Six Sigma... You name it. An essential and substantial ingredient of all these is common sense.

Most important insights are plain common sense. Or so they see, after you learn it. Like Peter Drucker's insights on business for example.

But Common sense is not commonly present. Most of our life experience is about aquiring this common sense. Why call it common sense if it is not common anyway? Perhaps the 'common' does not mean 'present everywhere', it probably means 'applies universally' to many things.