Common Sense

Just a very short post, as I want to ask a question. I find myself bemused by the term ‘common sense’. Could anyone tell me what is common about sense. I find that most of the time, people I come into contact with, be they random people in the street, other drivers or whatever, do not seem to have sense of any sort. Why do we say ‘common sense’? Sense does not seem to be very common to me at all.

Or is ‘common sense’ supposed to be that sense that is common to us all? Neither version fits well with the experimental data that I have been gathering recently.

So, dumb question, but if anyone can enlighten me I would be most grateful. Either that or just tell me to shut the fuck up and deal. Answers on a postcard please, or in the comments section if you prefer.