What is the coldest joke you have ever heard?

I have done the cruelest thing in my life. . My brother hit me. . When I was in primary school, I rummaged around in the grass near the school and dug out a test paper that scored more than ten points in math two days ago. The name on the test paper was a female classmate who was particularly annoying at that time. . I quietly put away the test paper. . After many twists and turns, I asked many other students her home address. . I ran after school in the afternoon for more than half an hour and personally delivered it to her home. . It is her father who opens the door. I said I was XXX's classmate. I found her math test paper the day before yesterday. Maybe she dropped it. I will send it with you. . Her father said thank you with a black face. . I wonder what happened to her. . Anyway, I remember not coming to school for several days. .