When training a group of Adult learners at work, I had the pleasure of teaching them quite a detailed application that required clicking both the right and left buttoms on the mouse from time to time. So far so good, until one participant put her hand up and asked why her mouse wasnt working when she left and right clicked.
Me : Well can you show me what you are doing and I might be able to help out.
Participant : Well when you say right click I push the button with my right hand and then when you say left click, I push the button with my left hand, but it doesnt work.
Me : Ok everybody break for lunch, I need a break. (I think I cried that day - it was day 1 of a 15 day course.