What a terribly boring video. Thankfully, they updated them by the time I served. The information was still relevant, however.
Things like how to find an unknown position from two known positions, back azimuths and pace count bring back memories.
I remember the land navigation course on Ft Knox, KY at PLDC. The most difficult point I had to find.....750 meters straight line distance away (most were 400 meters or less), across severe terrain (several steep draws and spurs). Being given grid coordinates, plot them on a map, and then navigate to them on foot across wilderness terrain - to find an exact point within 10m, and having to do so within a time limit, isn't exactly easy. A large portion of the group would fail to do so the first time around.
Night land nav was even harder. Thank goodness I've always had a good sense of direction, and already knew how to navigate (rudimentary) by the stars.