情不是曹操说来就来
[qíng bù shì cáo cāo shuō lái jiù lái]
'Qing Bu Shi Cao Cao Shuo Lai Jiu Lai' refers to romance (or any kind of feelings) which doesn't come just as wished for; here, Cao Cao represents the historical figure renowned for power but also impulsiveness, indicating that not all matters follow people's impulsive desires, especially true affection. The idiom 'Cao Cao comes when you say' is sometimes used sarcastically for things coming at the most unexpected times.