"The universe is my heart, and my heart is the universe" means "I believe that my consciousness is the origin of the world, and the world exists with the existence of my consciousness." The original sentence is: "My heart That is the universe, and the universe is my heart.” This is the view of subjective idealism, which originated from Lu Jiuyuan.
After Mr. Wang Yangming of the Ming Dynasty "enlightened the Tao in Longchang", he also said something similar: "When I first know the way of the sage, my nature is self-sufficient. Anyone who seeks to understand things from it is wrong." It means "There is all the potential to become a saint in my mind. It would be completely wrong to seek the conditions and principles of sainthood in external things."
Extended information
Lu Jiuyuan has been smart and studious since he was a child. He likes to inquire into the basics and put forward his own opinions. When he was three or four years old, he asked his father, "How can the world end?" His father laughed and didn't answer, so he meditated hard day and night.
When I grew up, I read ancient books and when the word "universe" was explained, I finally understood the mystery. He said, "The four directions up and down are called the universe, and the travels between the past and the present are called the universe. It turns out to be infinite, and humans, heaven and earth and all things are in infinity. Things in the universe are things within oneself, things within oneself are things within the universe, and the universe is me. Heart, my heart is the universe. All things are densely packed in a small space, filling the universe with all my heart. "
All things are unreal, only human consciousness truly exists. The material world, existence or nature only exists in human consciousness, only in human feelings, concepts or ideas.
Baidu Encyclopedia-Lu Jiuyuan
Baidu Encyclopedia-Subjective Idealism