You will never lose a battle if you know your own situation as well as that of the enemy.
如果你既了解敌人的情况，又了解自己的情况，你就永远不会输掉一场战斗。
敌人
You will never lose a battle if you know your own situation as well as that of the enemy.
如果你既了解敌人的情况，又了解自己的情况，你就永远不会输掉一场战斗。
Your enemy's enemy is your friend.
你的敌人的敌人就是你的朋友。
Your ignorance is your worst enemy.
无知是你最大的敌人。
Your worst enemy cannot harm you as much as your own unguarded thoughts.
你最大的敌人对你的伤害，不会超过你自己不加防范的想法。