The Yellow Emperor’s Classic of Internal Medicine: The inner hole of the heart.
Chen Changwen’s interpretation:
Everyone has a mind,
A healthy person, a wise person, has his mind, his mind on himself,
focus on his own business,
A stupid person, an unhealthy person,
He tends to wander, and his mind and heart tend to be on other people,
Being changed by other people’s emotions,
either care about the kindness of others, or care about the hatred with others.
Such a person is unhealthy.
Don’t be a boss if you don’t understand human nature.
Source: Chen Changwen Business Wisdom