找到一首不知名作者的类似诗的文章，讲得挺好，功夫熊猫里也引用了它的一句话。转载如下：

To realize the value of ONE YEAR, ask a student who failed a grade.
To realize the value of ONE MONTH, ask a mother who gave birth to a premature baby.
To realize the value of ONE WEEK, ask the editor of a weekly newspaper.
To realize the value of ONE HOUR, ask the lovers who are waiting to meet.
To realize the value of ONE MINUTE, ask a person who missed the train.
To realize the value of ONE SECOND, ask a person who just avoided an accident.
To realize the value of ONE MILLISECOND, ask the person who won a silver medal in the Olympics.

Treasure every moment that you have! And treasure it more because you shared it with someone special, special enough to spend your time.

And remember, time waits for no one.
Yesterday is history.
Tomorrow is a mystery.
Today is a gift. That's why it's called the present