I find it fascinating how many people are shocked by an actual rotation.


Here's a more visual representation of what he's doing on that bingo card.





As for learning the rotation, it really just comes down to repitition.

Practice it again and again and again until it becomes muscle memory, until you only need to glance at your hotbars to figure out where you are in your rotation

Until you don't even need to think about it because your hands do it automatically and you can concentrate entirely on looking at mechanics.