Learn to keep people dependent on you: to maintain your independence you must always be needed and wanted. The more you are relied on, the more freedom you have. Make people dependent on you for their happiness and prosperity and you have nothing to fear. Never teach them enough so that they can do without you.

I would suggest that while there is truth in this, there is also the alternative edge to this blade. While being an expert, wise sage, or some other form of designated professional increases our demand, the mob will also seek to consume every available moment of you as a resource. It seems that our human nature is to consume our resources into our own oblivion and that would include our human resources as well. It is wonderful to be need and in demand. The key is to know where and when to create boundaries. You will protect yourself and also create more demand by controlling supply.