Common sense is acquired knowledge. Unlike instinct, you are not born with it. Common sense is unique for each individual.
Most of us have gone through the frustration of dealing with people who do not seem to have common sense. Very often, common sense appears to be most uncommon and rare. Unfortunately it is true. Common sense is very uncommon. This is because what is common for you may not be common for someone else. Common sense is something that is acquired through experience. Since everyone goes through different experiences in life, common sense for each person is unique.
In England, it is common sense that shoes left outside the door by hotel guests need polishing, whereas in US the common sense is to throw them in trash. For the Japanese it is common sense to sit on floor if all chairs are taken, whereas for the French it is common sense to stand along the sides. For young drivers it is common sense to speed up on wide open roads, whereas for aged drivers it is common sense to drive near the kerb and make place for speeding cars. For most doctors, it is common sense to listen carefully to the patient, whereas for most lawyers it is common sense that their clients listen to them carefully.
Common sense varies not only by nationality, culture, age or profession; but also by education, upbringing, neighborhood, work place, etc. etc. Essentially everything that you experience in life shapes what you consider as common sense. Since all of us go through unique set of experiences in life, what we consider as common sense is also unique.
Whenever you come across someone, who does not seem to have common sense, look carefully. You will see a person who is different from you. There is no reason why your commons sense should be common for him or her.