because of hard questions on exams.. sometimes, students get tired on finding the solution on getting the correct answer.. and will come to an instance that they will not take it seriously if they pass or fail on the exam, hence, the result is that they just put some funny images or irrelevant answers to the exam's questions.. and it will catch the attention of the public, and we can say the "Life of a student is a not an easy part of growing up".
We need to strive hard to fulfill our dreams.