Which is a double whammy considering all of the other ways schools crush enthusiasm and willingness to explore. Because grades are a measure of "achievement" that discourages people from exploring new subjects or taking challenging courses outside their comfort zone, since that could lower their GPA. And because all course work factors into your grade, not just your ultimate competency in the material, that creates even more incentives to not try anything new. Struggling with new material for even a week or two could irreparably harm your GPA.