With typical human fickleness, they jumped from one extreme to the other.

于天生就动摇，容易从一个极端跑到另一个极端。

I've lived in this town for four years but still can't come to terms with the fickleness of its weather.

我在这座城了四年了。可是仍不习惯当地天气变化无常。

While she always criticized the fickleness of human nature, she carried on an unrelenting search for the ideal servant to the end of her days, even after she had been sadly disillusioned by Bessie.

她一方面总是批评人朝三暮四，另一方面她又持之以恒地寻找一个理想佣人。即使在贝西大大地伤她心之后，她还在找，一直到她死去。