"如果你既了解敌人又了解自己，你就不必担心一百次战斗的结果。如果你了解自己但不了解敌人，每获得一次胜利，你也将遭受一次失败。如果你既不了解敌人也不了解自己，你将在每次战斗中都遭遇失败。"

Simplified Meaning:

Understanding both your own strengths and weaknesses as well as those of your opponent is crucial for success. Imagine a soccer game: if you understand your team's abilities and strategies well, and also know how the opposing team plays, you can plan better and win more matches. If you only know your team's skills but are unaware of the other team’s strategies, then for every game you win, you might lose one because you weren’t fully prepared. However, if you don't know anything about your team's capabilities or the opponent’s tactics, you’ll likely lose every match because you are completely unprepared. In everyday life, this means that success comes from self-awareness and understanding the challenges you face. For example, if you're preparing for a job interview, knowing your own qualifications and studying the company can help you perform better. If you're aware of only your strengths but not what the company is looking for, your chances are half and half. But going in without knowledge about yourself or the job will likely lead to failure.