追星的日子里我很快乐
[zhuī xīng de rì zi lĭ wŏ hĕn kuài lè]
'I Am Very Happy on the Days I Chase Stars'. Here stars could refer to actual celestial bodies but more likely is meant stardom i.e., popular stars/celebrities/idols the person admires. This netname implies a passion for being a superfan and enjoyment from that life aspect.