饮马长城窟
[yĭn mă zhăng chéng kū]
'饮马长城窟' literally means 'drinking horses by the well at the Great Wall'. This phrase can be traced back to ancient Chinese poetry where it depicts soldiers resting and watering their horses near wells close to the Great Wall. The user adopting this might evoke nostalgia for ancient history, a connection with military valor or even a romanticized journey of hardships faced.