What does it mean that children don't learn what they are not suitable for?

It is not appropriate for children to learn.

It is very wrong for children to refuse to study hard. If a person doesn't study hard when he is young, and he doesn't know the truth of being a man and knowledge when he is old, it will be difficult to make a difference when he is old. Jade will not become a beautiful object unless it is polished and carved;

People who don't study and don't know manners can't succeed.

Children should be close to teachers and friends from an early age, so as to learn a lot of manners and knowledge from them.

Huang Xiang, a native of the Eastern Han Dynasty, knew how to honor his father and warm his bed at the age of nine. This is what everyone who is filial to his parents should practice and follow.