Something that happened in School

Today, just after assembly, my classmates strolled back to class, trying to waste some lesson time. We were then greeted with a particularly complicated Math lesson. Our teacher, who incidentally happened to be our form teacher walked into our class and we all settled down after an enthusiastic greeting. He then told us to take our textbooks out while he distributed a new worksheet.
Taking a glance at the questions on the worksheet, I thought this would be an easy chapter but I did not know what was I in for. After giving us a few worked examples, he told us to start working on the worksheet he handed out. Unable to comprehend the equations, I looked around and I could see the expression of confusion on most of my classmates' faces. It seemed like he was just gliding through the whole chapter and left us puzzled.

                                           

I felt irritated as I was not able to solve the problems. Looking at the worksheet again, I attempted the question. After a few tries, I was still unable to complete the questions and got frustrated.
Then, I tried my best to listen hard to the explanation provided by our teacher and attempted the question again. Finally, with much concentration, I managed to solve the question successfully and felt contented with myself. I realised that the question itself was not as hard as I believed them to be. With a good grasp on the concept, I could easily deal with the other questions. I learnt that I had to pay attention to the teacher in class so that I would not lose out.