(idiom) To be familiar with one's own strengths and weaknesses as well as those of the opponent; originally from [[孙子兵法|孫子兵法|sun1 zi3 bing1 fa3]]

A person of integrity will sacrifice their life for someone who truly understands and appreciates them; one is willing to die for a bosom friend.

Used to express that everything is enjoyable when one is together with a bosom friend; when you are with close friends, you can let your hair down.

To know the enemy and know oneself; to have a thorough understanding of both sides of a conflict or situation. This idiom originates from [[孙子兵法|孫子兵法|sun1 zi3 bing1 fa3]] (The Art of War).

Famous poetic line meaning as long as one has a true friend within the world, even the farthest corners of the earth feel like home; used to express that deep friendship transcends physical distance.

Know yourself and know your enemy, and you will never be defeated; a classic military strategy from the ancient text [[孙子兵法|孫子兵法|sun1 zi3 bing1 fa3]]

private or intimate conversation shared between close friends

a polite expression used to show appreciation for being treated as a close friend; literally meaning "to have the honor of being among your close friends"

know the enemy and know yourself, and you can fight a hundred battles without danger; used to express that understanding both your own situation and that of your opponent ensures success

to consider someone a close friend; to take someone into one's confidence

a close female friend of a man, sometimes implying a romantic or extramarital relationship

a man's close female friend or confidante; a woman who understands a man's heart and mind

A woman's close male friend or confidant; a male platonic soulmate.

Drinking with a close friend who truly understands you; used to describe the joy of friends sharing a deep conversation while drinking together

a scholar will die for a friend who understands him, and a woman will make herself beautiful for the one who loves her; an ancient proverb about loyalty and devotion to those who truly appreciate one's worth