This proverb has been used extensively since the old Greeks had it over the Temple of Apollo at Delphi.
The reason we mention it here is because you will use your own set of experiences, knowledge, emotions, feelings, instinct and skills as basis for your management actions.
It is essential that you recognize what your value system is, what your believes are, where they come from and how they impact your actions. We have pointed out in other articles the value of getting feedback and seeking this actively. This will help to see how your values and beliefs are shared and understood and how they help or hinder your managerial style. If you know who you are and where you are, you may be able to develop an understanding of where you want to end up. This is important to chart out your course throughout your career.
Here are some links with more encouragement and tips on the value of knowing yourself and how to go about it, including some advice from the marine website.