This is my favorite YouTube video, hands down. It’s called “Did you know?”, and it’s a simple slide show set to the soundtrack of “The Last of the Mohicans.” It shows slide after slide of statistics that prove how fast the world is changing.

It’s scary, fascinating and brilliant.

It was created by Karl Fisch, the Director of Technology at Arapahoe High School in Centennial, Colo. He made it to show to the teacher at the school’s staff development meeting. His audience has grown a bit since then. Since being posted on YouTube, the main video has been viewed over four million times. (There are many other versions and a “Did You Know? 2.0.”)