毕业后你不是我的毕业后我不是你的
[bì yè hòu nĭ bù shì wŏ de bì yè hòu wŏ bù shì nĭ de]
This phrase reflects an emotional breakup or estrangement after graduation, highlighting how a relationship changed. The user might have had close bonds during school but experienced a separation once they graduated, leading them to choose a nickname that expresses these complicated sentiments about post-graduation relationships.