I had a computer programming professor in college in the late 70's who would always exhort us to use common sense. I had never even seen a mainframe before college. How was I supposed to apply common sense to something so alien and absolutely not common to me? Still, he was one of the profs I had.
This concept reminds me of one of my favorite quotes: " Begin challenging your own assumptions. Your assumptions are your windows to the world. Scrub them off every once in a while, or the light wont come in." - Alan Alda