When the boy is twenty years old, he thinks he is very handsome and will become more handsome, but when a man is thirty years old, he knows that he is not handsome and has never been handsome.
When the boy is twenty years old, he often feels that he is very mature. When a man is thirty years old, he often feels that he is very naive.
When the boy is twenty years old, he feels that he understands a lot of things. When a man is thirty years old, he feels that there are too many things he does not understand.
When the boy is twenty years old, he feels that he is very strong, but when a man is thirty years old, he feels that he is very fragile.
When the boy is twenty years old, he thinks giving up is a kind of inability, but he often gives up. When a man is thirty years old, he knows that giving up is a kind of wisdom, but he often can't bear to give up.