We usually think that anything can be taught,given the right teachers, etc., but that might not be entirely true!
A friend, recently said that common sense can't be taught!
But that is only true to a point.
Our cognitive brain system has 3 parts ( I am not going to explain them here):
1. Autonomous
2. Algorithmic
3. Reflective
Now I.Q. tests measure #1 & #2 but not #3 and that is where we all have our common sense (if we have any).
If, while a person is young & teachers teach reflective concepts, then common sense can be learned. BUT ONLY to a point! But it is easier for a child to learn these concepts.
An adult MIGHT learn a bit but only on a few things.
Can ya lose common sense? Yup! Usually through an accident, disease, or mental anguish.
Can ya get it back what ya lost? Chances are 50/50 & it depends on a LOT of factors.
So my friend was right but only to a point. Us adults will just have to fumble along if we don't have a fair dose of common sense.
Like they say: Common sense isn't so common!