“If you know the enemy and know yourself, you need not fear the result of a hundred battles.”Sun Tzu · Arta războiului · -500 · capitolul 3
Self-knowledge and knowledge of the adversary eliminate the risk of failure in any confrontation.
Sun Tzu formulates here the fundamental principle of strategic intelligence. Knowing your own strengths and weaknesses, as well as those of the adversary, means you can anticipate moves and act where you are strongest. For example, a chess player who knows he is weak in defense but knows his opponent attacks chaotically can wait for the mistake. Without this knowledge, every battle is a lottery.
Why it matters In a career, knowing your skills and studying the competition or the market is the key to success; ignoring this rule means acting blindly.