孤独久了已成性
[gū dú jiŭ le yĭ chéng xìng]
The username translates to 'Solitude for Too Long Has Become Habitual'. Here, it suggests that due to prolonged periods of loneliness, one has developed an enduring nature. They may feel accustomed to the company only they keep, perhaps becoming less open or responsive to forming bonds with others over time.