달도 차면 기운다
Even the moon wanes when it is full.
Used to say that no one can expect to be popular or at their best forever.
The cycle of the moon means that after it grows (waxes) full ,it then begins to shrink (wane) to a new moon. 차다 means "to be full," and 기울다 means "to shrink." The moon's cycle can be compared to the life cycle of man.
Every tide has it ebb.