It makes a world of difference as a student when your teacher or professor is actually engaged in the material they are teaching you. Think back to when you were in the classroom last. Do you remember classes where professors stood at a podium in front of the class and droned on, practically reading from a textbook for an hour? Or are the classes that stick in your mind the ones in which professors captured your attention with interesting exercises and experiments that made the material tangible and interesting?One fantastic physics professor went viral for doing just that. He may be in his 70s, but he approaches his classes with energy, enthusiasm, and visually stimulating demonstrations that illustrate physics principles and make the material that much easier to understand and retain. A student compiled videos of his demonstrations throughout the semester and shared them on Twitter so everyone could share in the joy of this man's class.And they did! The video has been watched 21 million times, retweeted over 420,000 times, and like 1.6 million times. It probably resonated with people because everyone knows what it's like to be in a class where you're falling asleep at your desk and unable to pay attention. And everyone deserves an engaged and dynamic teacher like this guy, Professor David Wright, who teaches at Tidewater Community College in Virginia.The responses are overwhelmingly full of appreciation and love for teachers who go above and beyond for their students. As everyone knows, the teachers you have can make or break your learning experiences."OK first off this is adorable," one Twitter user wrote in response to the video. "Second off [this is] a prime example of how professors can make class interesting/exciting EVEN if the subject is boring or super hard. This man is 70 and still entertaining his class!!!"This is so true. When I took physics in high school, I hated it. I couldn't connect with my teacher's style and didn't feel like I retained the information. If I had a teacher like Dr. Wright, my experience of physics might have been totally different. And the fact that he's still this enthusiastic for teaching in his 70s says a lot about who he is as an educator and a person.In an interview with BuzzFeed, Dr. Wright said that he's been teaching at Tidewater for his entire career. It was his first job out of grad school 45 years ago. "I never thought I'd be at the same place my entire life, but it's been a wonderful place. I've really enjoyed it," he said.Because many of the students taking his physics class aren't usually engineers or hard science majors (most of them are completing a prerequisite), he has found creative ways to keep the class enjoyable for all through these demonstrations. In the video, he lies down on a bed of nails, makes ice cream using liquid nitrogen, gets pulled down the hallway on a skateboard, and more.When his student, Erica Church, posted the compilation of his demonstrations on Twitter, she never expected it to go as viral as it did. As more and more reactions and likes and retweets came pouring in, Erica emailed Dr. Wright to inform him of his sudden, unexpected fame and thank him for an unforgettable semester.His response was heartfelt and adorable: "Thank you very much for sharing that with me," he wrote. "It was an amazing semester because I had amazing students." Is this not the most amazing story of the whole year? And just under the wire, too."I was just amazed. It's incredible. I'm blown away." Dr. Wright told BuzzFeed. "I've often hoped I could reach people. I see my mission in life as to get people excited about science, so it really remains relevant, exciting, and fun. I've always tried to do that in my class, but I never expected to do that on this scale."Maybe someone will see the video and think, oh, I should really take physics and learn more about this remarkable stuff that's going on out there." He tells BuzzFeed that he himself had a special teacher back when he was in sixth grade, and he was able to go back after 50 years and explain that he was the inspiration for his career as a teacher. Teachers with passion and enthusiasm for their careers and for their students change lives.