I think common sense is very basic-it's like the survival instinct. Once you try to put a campfire out with your face-it's commom sense that you won't do it again.

If you are waiting for an elevator and don't bother to look down when the doors open, and there is no elevator-common sense dictates that from now on you will look to make sure there is an elevator there before you take that first step.

Same thing with oncoming traffic. Once you watch someone get squashed like a bug because they stepped in front of a moving bus without looking-chances are you will have the common sense not to do it yourself.

Survival-logic-common sense. It doesn't much more basic than that.