So 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.
ZhuangziWhen there is no more separation between 'this' and 'that,' it is called the still-point of the Tao. At the still point in the center of the circle one can see the infinite in all things.
Zhuangzi