From a quick google search common-sense is defined as “good sense and sound judgment in practical matters.” This definition sums up common-sense fairly well. But I look at common sense as the ability to make fewer mistakes and make better decisions.
Education is something most people stop after finishing their formal educational. We stop reading books. We stop learning new skills and ideas. We get into the same habits of going to work and paying bills. We come home play with the kids, watch TV, and sleep. We wake up the next day and do it all over again.