再好的雨终究输给太阳再好的天终究输给晴天
[zài hăo de yŭ zhōng jiū shū jĭ tài yáng zài hăo de tiān zhōng jiū shū jĭ qíng tiān]
Even the best rain will eventually be overwhelmed by the sun; the nicest overcast sky will still yield to clear skies. This conveys a sentiment that all things change and not every pleasant moment can last forever.