I don't understand the meaning of dark at night during the day.

The phrase "I don't know the darkness of night by day" means that day and night are two completely different experiences and feelings. People who haven't experienced some kind of difficulty or pain can't really understand the feeling and influence brought by that kind of difficulty or pain.

The superficial meaning of this sentence is that day and night can't exist at the same time, so the environment in which they exist is completely different, because they can't understand each other. It can also be understood that you can't fully understand and appreciate the feelings of others without personal experience.

This idiom can be used to describe people who lack experience or knowledge, and they often can't really understand the essence and connotation of things. They can't understand other people's feelings and experiences because they haven't experienced them personally.

In addition, this idiom can also be extended to some problems encountered in education, training and growth. If someone lacks experience and knowledge, it is difficult to understand the complexity of work and life, and it is difficult to cope with different situations and challenges.

Therefore, the idiom "I don't know the night during the day" reminds us that only by learning and growing through personal experience can we truly understand and experience the diversity and complexity of life.