我的城府不深不浅
[wŏ de chéng fŭ bù shēn bù qiăn]
It means 'My hidden thoughts are neither too deep nor too shallow'. City wall and moat symbolize one’s ability to keep secrets and control emotion in Chinese culture. This implies that the user may have some level of depth, not completely transparent, but not extremely complex either - somewhere in between simple and complicated in matters of the heart or thoughts.