His words are always sweet on the surface but venomous underneath.

My father was diagnosed with ankylosing spondylitis.

He said, 'A nameless star comes out in the evening,' teaching me that achieving a goal is not easy.

After many years of effort, he was finally able to achieve his goal and make a name for himself.

My grandfather contracted poliomyelitis when he was young.

He was able to achieve career success and fame after much hardship.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.