【译文】仁的道理，要点只是一个“公”字。

Every man has his secret sorrows which the world knows not; and often times we call a man cold when he is only sad.

Investors should focus on what they can control: costs, diversification, and time horizon.

赏析：通过忘记脚、忘记腰、忘记是非纠纷来说明内心的舒适和自在，强调了要放下杂念和纷争，保持内心的平静。