好景不常
The morning sun never lasts a day.
The longest day must have an end.
Every day is not Sunday.
A wonder lasts but nine days.
eg：The social disorder destroyed the once prosperous town, the morning sun never lasts a day.
中英俚語俗語來源：王勃 · 滕王閣序：" 好景不常，盛延難再。"
反義詞：天下無不散之延席 Merry meet， merry part.
