I have spent quite a bit of time recently working with students who have just received their report cards. Inevitably, the instinct is to focus on the results ONLY as an indicator of what has already happened and as a fixed determinant of learning.
Certainly, one's grades should be a measurement of learning from the period of time in which the grades are determined. However, only viewing grades as a final measure cuts out the growth mindset from the picture.
My suggestion to students (and parents) is to balance this view of grades with a growth mindset. Instead of only focusing on them as a fixed measure of what was, use the grades as a starting point for what can be. In other words, use the current results to determine what is a reasonable vision of "better" and then work on an action plan that addresses "getting better."
Chances are, by focusing on getting better, you will be more satisfied with your next set of results.