"To be Irish is to know that in the end the world will break your heart."

Perhaps the most counter-intuitive truth of the universe is that the more you give to others， the more you’ll get. Understanding this is the beginning of wisdom.

因果模型是理解世界的关键。

"The truth is rarely pure and never simple."

解释：以芍药相赠，以文无（一种中药）相招，展现了中药在人际交往中的特殊意义。