Yeah, I was thinking this as well. This box and line diagram style is so far away how you would implement many of these structures that you might not recognize them if you saw them.
Back first year when we had linear algebra, I was pretty much the only guy who absolutely aced the exam. Not because I was the smartest or hardest working, but because I applied everything we learned to a game I was building, a 3d spaceship simulator. Vector products, planar projections, rotation matrices, I mainlined all of it, I pored over the book in my spare time with great enthusiasm. For the rest of the class it was just yet concept after abstract concept being piled on with no place to apply them.