“If one loses a silver coin, he should praise Hashem as though he found a silver coin. And if he loses two silver coins, he should be happy as though he found two silver coins. The same is for every bad thing that happens to him; he should think that the bad is good, because the extent of the good is in accordance to the extent of the bad.” ~ The Vilna Gaon

In other words, we know that everything Hashem does is for the best.  Sometimes we lose one coin and that is sufficient, but when we lose 2 coins, Hashem is saving us from something even more terrible.  So we need to be even more thankful!