情不知所起一往而深恨不知所踪一笑而泯
[qíng bù zhī suŏ qĭ yī wăng ér shēn hèn bù zhī suŏ zōng yī xiào ér mĭn]
Taken from classic Chinese poetry, it means: 'love starts unknowingly and runs deep; grudge disappears without trace with just a smile'. This expresses the profound nature of emotions, how love begins unexpectedly and hatred ends simply.