What are some things that every computer user should learn? What things do you wish every computer user knew? What are some of the biggest benefits that individuals and/or society could reap if computer users learned these things?

Please boost, I honestly want as many serious answers as possible. Feel free to answer variations of the question for different levels of "computer users", such as programmers, office workers who use a computer 4+ hours per day, phone-only users, etc.