I was sitting in one of my high school classes, being told in a loud voice, “Class, today is an important day, and we are going to watch history on this television." My teacher sang as he rolled a cart with a basic color television to the front of the room. "Do not ever forget what you are about to see," he said.

Mr. Gastler, my economics teacher, was an interesting man, to say the very least. He was a flamboyant character who taught the most boring topic in the most nontraditional ways. He made the mundane seem exceptionally important and relevant to every one of his students. Dick was known by many families and had a story to tell to everyone he met, either on the street or in the hallways of Denfeld.

He was most famous for his green leisure suit, which was used to raise money for fundraisers targeting hunger. He made a deal with students: He would wear the suit every day until they reached their fundraising goal. When enough money was raised, in true Olympic fashion, Dick set his now infamous green leisure suit on fire — in a garbage can on the side lawn of the school.

Mr. Gastler loved his hometown of Chaska, Minn., and the life he lived when he was there. We heard endless stories about Chaska, the people, the town's German traditions, and how proud he was to be part of them. Dick would sometimes even break into speaking German while teaching. He was a charismatic character. You never knew when he would start speaking German or start singing — and when I say singing, one must imagine a loud, booming operatic baritone voice.

Teaching was his life, and he paid close attention to all his students. He focused on the positive traits in all of us, not just a few select students here and there.

When Mr. Gastler turned on that television, we sat in silence and in complete awe. It was indeed history in the making on Nov. 9, 1989, 30 years ago today, as the Berlin Wall fell in Germany.

It was nighttime, and people from all over Berlin were congregating at the once intensely secured Cold War relic. There were no guns, no patrols, no shooting of people crossing over the wall illegally. On this day, the people were contagiously joyous as they climbed all over the wall, something that had never been done without dire consequences. All you could see was a sea of people standing or dancing on top of the Berlin Wall. Dick sat silently, wiping tears from his face with his handkerchief.

I didn't realize the true meaning of his visible joy until the following summer when, for a month, I met and stayed with my German pen pal and her family. We traveled all around. On a trip to Tirol, Austria, in a restaurant, we met an eastern Germany family. My host family started a discussion with these intensely happy looking Germans. The woman of the family told us with pure glee on her face, "We are free to be humans again. We can travel wherever we want (and) whenever we want."

It made clear the significance of that moment, sitting in Mr. Gastler's economics class, watching tears flow down his face as we all viewed the Berlin Wall coming down.

I was greatly saddened to hear that Mr. Gastler passed away on Oct. 15, 2015. He was a testament to the good in the world and to doing well by others. A quote of his, which summed him up for all of us who knew him, was: “While we have the opportunity, let us do good to all people.”

This notion rings loudly and clearly in my mind. It was one of his greatest lessons. I am honored to have shared such an important historical moment, particularly because I shared it with a teacher who lives in the hearts of every one of his students, Herr Gastler.

Tracie Treharne grew up in Duluth and is in Germany now working for the military as a speech and language pathologist. She graduated from Denfeld High School in 1990.