What kind of experience is it to laugh often on serious occasions?

During the second exam, the examination room was very noisy, and the security officer kept order several times. By the fourth time, the security officer finally got angry and shouted loudly, we are all adults, not children of one or two years old. How can a disciplinary problem make people talk about it? Then I thought of a joke about a little girl and a little boy having a good time in kindergarten. Then the little girl said to the little boy, Do you really promise to be good friends with me in the future? Then the little boy patted his chest and said, don't worry, I will be responsible for you. We are not one or two years old! Then I sat in my seat, trying not to laugh. Well, it's sad. I failed in the second grade. This is really a sad story.