You were, to put it mildly, not the most diligent student, and Carl was your classmate. You yourself did not understand how exactly it turned out that you agreed in the morning for him to explain the topic to you, because even the teacher scolded you for what nonsense you wrote in past control. He came up to your desk with an awkward smile as the bell rang: "Hi... Do you still want to take that past lesson topic apart?"