The guy with the best grades in class will tell you that examinations are the true test of knowledge. The one with worse grades will say otherwise. So, it is left to the average guys like us to decide
In the end, I think examinations are just examinations. Knowledge is not the only factor that influences their outcome. Time and chance come to play a major role. But when a student continues to do well or badly consistently in their examinations, then it's quite convincing how much they know. Irrespective of examination results, we all should pursue knowledge.