What did Einstein mean when he said -
"The most incomprehensible thing about this world is that it is comprehensible"
As scientists find out answers to some questions, more questions come up. This why, why, why........ may appear to be endless and the final answers may require philosophy. So, if an assertion is made saying that the nature is comprehensible then it is difficult to understand or comprehend that assertion. That assertion is incomprehensible according to the quote.