The purpose of teaching is not completing all the curriculum nor finishing tasks. The purpose of teaching is giving them new window for investigating the world. That is like brandnew point of view that can be only got after through individual dedication.
The purpose of teaching is showing the better future and attracting audience to dive into another new world. To accomplish that mission, speaker have to give them instinct and motivation to pay a cost before getting return.
If we teach, audience will soon forget.
If we invite, they will move.
If we give them role, they will involve.
Involvement and empowerment is far beyond teaching. You have to make them find why they need the new world and why the new world needs them.