We've all said it during a disagreement or had someone say it to us, "That's just common sense." The problem is, common sense is not common because similar to perspective, common sense is based on culture, education, background, and environment. Taking off my shoes when I enter the house or eating with chopsticks is common to me, but you may find those tendencies strange. So next time you want to tell someone something is common sense, remember that it's common sense to YOU and not to everyone.