This is just my interpretation.
For the "worldling" self and my-world exist and are real beyond
For the noble disciple, on the noble eightfold path, self and
my-world are understood as having come-to-be, by being fabricated
by the mind. They are not real. He is working towards their
cessation. So because he sees how this "world" has arisen, he
does not think - "it does not exist." And because he sees how
this "world" will cease, he does not think - "It exists."
For those who are enlightened this "world" has ceased.