What is the poem "If"?

If you are a big river in Wang Guozhen, why should you care if others treat you as a stream? If you are a mountain, why care about others treating you as a flat ground; If you are spring scenery, why sigh for the withering of a flower; If you are a seed, why worry that there is no result yet; If you were you, smile quietly and be fearless. If-Wang Guozhen, if you must go, how can I keep you? Even if I keep you, your heart will float in the distance. If you are destined to leave and never look back, why should I worry alone? Even if Lacrimosa can't wash away my troubles all day, you should go smartly. There are spring and autumn in life, so there is no need to look back. I'm not without you.