There was a man who walked by the river with his girlfriend. Suddenly his girlfriend fell into the river. The man hurriedly jumped into the water to find her girlfriend, but he could not find his girlfriend. He left here sadly.
A few years later, he revisited the old place. At this time, he saw an old man fishing, but the fish caught by the old man had no water plants. He asked the old man why the fish did not have any water grass. The old man said: This river had never grown the water grass. Speaking of this, the man suddenly jumped into the water and committed suicide.
Why?
