This is going to be a waste of time, I thought as I descended the gray stairs to the gym. My friends surrounded me, filling the air with jokes and laughter. We were headed to the gymnasium for a bullying seminar that would last two periods. 150 minutes. I am not one to question missing class for a school-organized event, but today I would be missing study hall. Unfinished homework hung over me like an unstable roof about to collapse. I had a biology test and a few ignored assignments from last night, and the good student inside me ached when I heard I would miss that free period.

But it wasn't just the urgency of unfinished school work that made me reluctant to attend this assembly; the topic made me uneasy too. We were all a little on edge when we heard from our parents that some serious subjects would be discussed today, things that weren't discussed openly in teenagers' lives, things that rarely crossed our minds. A speaker was going to tell us the story of his son who committed suicide after being bullied. His name was John Halligan.

I sat near the front with my friends. Mr. Halligan began by introducing us to his son, Ryan, showing us a slide show with photos of a dark-haired boy as a toddler, a child, and then a teen. We watched as he slowly transformed from a happy kid to a slightly awkward teenager. He had a strange smile – like a mask that hid his pain. Mr. Halligan began telling us about his family, mostly his son. He told us of Ryan's early developmental problems, the bullying due to his slow learning, and his advice to his son.

Mr. Halligan's voice varied, but was always filled with emotion. First it was full of affection as he spoke of Ryan as a child, then pain as he described Ryan's bullying and suicide, and then anger as he described the boy who bullied his son. He told us that Ryan had stood up to the bully, and the torment at school had stopped – for a while. He spoke of how Ryan had befriended the bully, sharing personal details with him. And how, after that, the bullying behavior reignited.

All the while, I stared down at my running shoes, memorizing every scratch and scuff. Gone were thoughts of homework, replaced with concern and a slight sense of guilt. I too have teased and humiliated someone many times. If you are reading this and thinking to yourself that you have never done anything to put another person down, I don't believe you.

During these profound 150 minutes of my life, I thought over every nasty thing I had ever done that affected another person. Mr. Halligan spoke of how the bully spread a horrible rumor about Ryan. I remembered every rumor that had escaped my mouth. I thought of every sly comment I had made, every joke that put someone in a negative light.

Mr. Halligan told us that no one had stood up for Ryan; bystanders had abandoned him. I desperately wanted to believe that I would have stood up for his son, that I wouldn't have been another person in the faceless crowd who had just watched. But I already knew the truth, though my conscience was too afraid to admit it.

Mr. Halligan continued, telling us about a girl Ryan had been chatting with online, whom Ryan thought he had a relationship with, a special bond. She later told him that she was just joking around and that she and her friends had laughed at his responses. He told us that his daughter found Ryan dead on October 7, 2003, and how his world was shattered.

He ended by saying that since Ryan's death, he has been visiting schools to share his story. He spoke of how he had received many supportive e-mails from students and parents. He explained that each time he heard that Ryan's story had changed someone, it helped heal the hole in his heart.

I can still remember that moment as if I had just experienced it. The gym was filled with students but was totally silent, which eerily reminded me of the thousands of white tombstones and the stillness at Arlington National Cemetery which I had just visited. Some students were crying, some watched intently, and some shifted uncomfortably in their seats.

I believe that those 150 minutes changed me. I realized that what I once considered meaningless jokes could be a fatal poison for the targets of that teasing. I was just an average teenager who used humor to get people to notice me. But I believe that I have now been changed for the better.