I thought it interesting that in this quote the aspect of knowing yourself was included. I call it being “self-aware." If you don’t know who you are and what your capabilities are you will put yourself in poor situations.
Then there is knowing your business. I don’t know if you need to be an expert in all facets of what profession you are in, but being knowledgeable is important to not making the wrong choice. Isn’t the fear of making a mistake, the factor that freezes many people in place and keeps them from doing anything.
Lastly, he includes knowing your people. Do they know themselves, do they know their business and then if you are echelons above line people, do they know their people? It comes down to whom do you trust? When you know who to trust with your professional life it all becomes much simpler.