It seems obvious doesn't it? On a forklift course they want to learn. That may not be the case as the boss may have told them to attend.
The items above are just a small selection of what the audience may want intended to clarify the subject.
Of those above, the only one you can be certain of is the last one: to be safe.
You need to try to ascertain exactly what your trainees want and tailor you training course accordingly. Generally a forklift instructor will play on the things that appeal to the trainees such as safety, more money etc.