Motivation is the most important factor in any learning environment.
First and foremost, students must be highly motivated to learn. Motivation will be the driving force that makes students stick with it even when they are having trouble understanding information being presented during training. Indeed, any problem with learning can be overcome if the student's motivation is high enough. But just as important, the instructor must also be highly motivated to teach. They must have a burning desire to relate information during training in a way students can understand.