Within the Boundary Monument, Dida once told Lu Xun that his perception could extend beyond the Western State Border.
It didn't specify the exact distance, only stating it was "just a little bit".
Obviously, a 'little bit' from the mouth of a monument over a hundred meters high, and 'a little bit' from us humans who are just over a meter tall, are not the same thing at all.
The 'little bit' it was referring to, could very well be billions!
Since leaving the Boundary Monument, Lu Xun could always feel Dida 'watching' him depart.
This continued even after he had exited the Western State Border, arriving above Lost Forest, he still felt its 'gaze'.
Not sure whether it was just bored, or really relunctant to let Lu Xun leave, it watched him all the way.
Clearly, the dangerous situation that Lu Xun later encountered had also been perceived by Dida.
As for why Dida had told him to move a mile further, Lu Xun didn't understand.
But he chose to trust it.
