as someone that can do it, its very hard to place your mind back and realise they dont know what your saying and its not easy, my most recent example is prophang, everyone said its easy, eas it hell till it snapped, then wow, easy.
driving instructors get months of training so they can do this, us poor instructors dont, trial and error, we learn as much as the students!

the flip side to student brain over load, is instructor brain fade as the student gets better and you stand there for 10-15 mins with nothing to do. you can solve this by pulling your sticks right over, then letting go of the switch for a second or two keeps the student guessing too LOL