This proverb means that true power comes from knowledge. No individual or nation can achieve in life without knowledge. when you know things beyond, it gives us power.
A knowledgeable individual has the more power to foresee the future outcome because there os no end to knowledge. Ther is no limit to what can person can learn. Even big problems can be solved if we have the knowledge of solving it and more knowledge thw more powerful you've become.
Knowledge is more superior than our physical strength. Knowledge makes us informed decisions. knowledge is npt necessarily learned from books, it could come from experience and sometimes it can come from just watching other people's lives.
Without knowledge of what you are doing you cannot have the power to control it. Even a single word No when you have the knowledge is a great power and people will likely bow to you because you're empowering them. Thus, knowledge is power.