“If I could use a time machine, I would go back to the time when the grading system was invented and I would destroy it. Because of its invention, teaching ceased to be a calling and became a profession. I can only imagine the amount of potential we kill every time teachers give a student a grade of 5. A grade is but a number. Never let anyone judge you by a number, much less yourself. The day you start caring about your grades is the day you stop learning. A card of excellence is just a piece of paper. It will rot. But the knowledge you get because you wanted to learn—that’s yours forever, or you could pass it on.”
Link: When learning ceases.