You are not fish, How do you know the happiness of fish

I finished all the mid-term exams. as soon as something finished, all the painful memory disappeared immediately. I may disappionted by bad grades, but I really do not care that too much. All the current life is an extra for me, I have nothing to complain. When I heard that my Chinese professor said the sentence, "You are not fish. How do you know the happiness of fish", is his favorite, I was excited. I cannot have more communication with him, but in this point, I very happy that he could understand. I also like that life is suffering, the origin of suffering is from attachment.