我姓虞却没有七秒记忆
[wŏ xìng yú què méi yŏu qī miăo jì yì]
My surname is Yu, but I don't have a seven-second memory. This is referring to the stereotype about fish having a very short memory span. Perhaps the user is surnamed Yu (which has a similar pronunciation as 'fish' in Chinese 'yu'), but unlike fish, they have a lot on their mind, implying their own ability to remember or recall more than expected from someone with their last name.