Examinations are the ultimate test of the student.Even if one is doing his/her best during school/college days and confidently handling any academic questions until unless he/she scores good marks in Exams/Tests one will not be recognised in his/her domain.
So One should work hard and also plan his/her studies to achieve best marks in the Examinations.May be one should first assess his strengths vis a vis weeknesses and try to improve his expertise in a calibrated manner.