深知自己不重要还自欺欺人
[shēn zhī zì jĭ bù zhòng yào hái zì qī qī rén]
The person understands that they're insignificant yet continues to fool oneself. With such a nickname, a person acknowledges their own inferiority and lack of importance, but at the same time cannot accept it, leading to constant self-deception and internal struggles, which also hints at an overly strong sense of inferiority.