If you persist in trying to attain what is never attained (It is Tao's gift), if you persist in making effort to obtain what effort cannot get, if you persist in reasoning about what cannot be understood, you will be destroyed by the very thing you seek. To know when to stop, to know when you can get no further by your own action, this is the right beginning!
ZhuangziWhen people do not ignore what they should ignore, but ignore what they should not ignore, this is known as ignorance.
ZhuangziSo if loss of what gives happiness causes you distress when it fades, you can now understand that such happiness is worthless. It is said, those who lose themselves in their desire for things also lose their innate nature by being vulgar.
ZhuangziLove of colors bewilders the eye and it fails to see right. Love of harmonies bewitches the ear, and it loses its true hearing. Love of perfumes fills the head with dizziness. Love of flavors ruins the taste. Desires unsettle the heart until the original nature runs amok. These five are enemies of true life. Yet these are what men of discernment claim to live for. They are not what I live for. If this is life, then pigeons in a cage have found happiness!
Zhuangzi