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.

He is learning the art of painting.

He solved the problem using that technique.

He defeated the enemy using that technique.

He lost everything.

She is planning a date with her current boyfriend.

My boyfriend gave me a gift.

Everyone was surprised by the news.

It's better for him not to know the truth. After all, ignorance is bliss.

He is feigning ignorance about that problem.