橡皮擦不掉的距离铅笔画不出的界限
[xiàng pí cā bù diào de jù lí qiān bĭ huà bù chū de jiè xiàn]
Literally meaning 'The distance that eraser cannot remove, boundaries pencil cannot draw.' A creative metaphor expressing feelings of frustration with unchangeable distances (in either physical or emotional terms) or undefined boundaries