Horror reasoning story: Why did my brother suddenly go crazy?

This ... this sentence, I know what it is at a glance.

Is it ... or not

A brother and sister, one day my brother went crazy and killed the whole family. Then the police came and my brother was arrested, sentenced and executed. Many years later, the girl told her fortune and asked.

Why did my brother suddenly go crazy?

The fortune teller said: Your brother is not crazy.

The girl asked again, then why did my brother kill our family?

The fortune teller said, no, your brother only killed one person.

In fact, the girl was mentally ill and killed her family, and then her brother couldn't bear to go to jail, so he took the blame himself. The girl who was sick and killed only remembered that her brother had killed someone and was sentenced to death, completely forgetting that she was the murderer. The fortune teller said that the girl's brother only killed one person, and the person he killed was himself. He decided to take responsibility and die.

In fact, this story is a bit touching.