"You can't walk with your head down while looking up at the sky."

The moral of this sentence can be understood as: "When a person does not have enough strength and status, he should not be arrogant and pretend to be aloof, but should learn to be ordinary and low-key in life and work."

The moral of this sentence can also be understood as: "When a person does not have enough strength and conditions to pursue someone with much better conditions than himself, he must work hard and strive for what he can achieve." Your own conditions are worthy of the person you are pursuing.

The meaning of this sentence can also be understood as: "A person does not have enough strength, status, and conditions to retaliate against someone who has bullied or hurt himself or his family." When there is an enemy or resentment. You must learn to hide yourself and enrich your strength in a low-key manner so that one day you will be able to take revenge.