Meaning:
Literally translated as “8 grams of carp,” this term has nothing to do with the edible fish. First appearing at tieba.baidu.com, this is actually the joking way to say someone is “impossible” and won’t listen to other people’s reason. This is because both this phrase and the one it is used in place of (不可理喻) has the same initials in pinyin. Netizens often use it when they argue with people.
Example:
A: 小丽说明天的聚会她不来了，因为她的论文没写完。
Xiǎolì shuō míngtiān de jùhuì tā bù lái le, yīnwèi tā de lùnwén méi xiěwán。
Xiaoli said she wouldn’t be able to come to the party tomorrow, because she hasn’t finished writing her paper.
B: 这个聚会不是她召集的吗？简直八克鲤鱼。
Zhè gè jùhuì bùshì tā zhāojí de ma? Jiǎnzhí bākèlǐyú。
Isn’t the party initiated by her? She’s just impossible!
A: 可是我们都通知了那么多人来参加。
Kěshì wǒmen dōu tōngzhī le nàme duō rén lái cānjiā。
And we have asked so many people to come.
(Edited by Stephanie Yang)