A man crossing a river sees another boat drifting toward him. If the approaching boat is empty, even a hot-tempered man does not become angry when it collides with his own. He simply deals with the obstruction.
But if he sees someone aboard, everything changes. He shouts for the person to change course. If the first warning is ignored, he shouts again. By the third, he is cursing.
The collision is the same. What produces the anger is the mind added to the other boat: someone saw me, could have acted differently, and chose not to.
Zhuangzi turns the image inward. A person who can move through the world without constantly projecting and defending a self becomes like the empty boat - difficult to injure through insult.
Source: Zhuangzi, chapter 20, “The Mountain Tree,” James Legge’s public-domain translation. Retold.
What it argues
Events become personal offenses when we assign hostile intention to them. The empty boat creates inconvenience without insult.
Use it for: road rage, online conflict, attribution error, and separating harm from inferred intent.