capriciousness       
noun [ U ]  literary uk/kəˈprɪʃ.əs.nəs/ us/kəˈprɪʃ.əs.nəs/
 善变
the quality of changing mood or behaviour suddenly and unexpectedly
  Her capriciousness made her difficult to work with. 她的善变让人很难和她共事。 
 See: capricious
 - More examples
 - When you check your bag for a flight, you consign your luggage to the capriciousness of baggage-handlers.
 - Experts have grappled with the capriciousness of giant panda reproduction across several continents.
 - The capriciousness of the media can't fully explain why the murder was barely mentioned.
 - Despite his capriciousness, he's known for possessing a keen mind.