Are marks in exam true representative of the knowledge one has ?

I don't know what's the answer to this question. But I am sure that it will not be right to say that they are the true representative. I have observed in many numbers of cases that people who know the subject well have scored less marks than the people who knew less. I am saying this after removing those occasional cases of silly mistakes. So what's the reason behind that? Are the exams are not designed to test the true knowledge? Isn't it possible to do that?

I don't know the answers to these questions. I will share what I think the reason is. Cracking an exam needs more than just knowledge. It requires the skill to solve the problem with the information provided by finding the correlation/pattern in the given information.

I need more thinking which I am unable to do at this hour of the day. Let me try to build on this some other time