Love your friends with your eyes closed, but love your enemies with both eyes open.
In poverty, friends are few; in prosperity, acquaintances are numerous; in affluence, associates are countless.
A flower takes a while to grow, but can die in an instant; this is how it is with trust.
Learn from acquaintances, and you are clever; from friends, and you are intelligent; from enemies, and you are shrewd; but learn from all, and you are wise.
A shrewd enemy will teach you more than a foolish friend.
Those who laugh with you when you laugh are acquaintances, those who cry with you when you cry are companions, and those who do both are friends.
Never set fire to a bridge while you are still crossing it.