Yeah...I think we have to use some context clues in interpreting this particular piece of advice. Clearly, he's not suggesting you verify all assumptions as it

Yeah...I think we have to use some context clues in interpreting this particular piece of advice. Clearly, he's not suggesting you verify all assumptions as it would take millenia to verify literally all the assumptions that one makes when writing a complicated program. Personally, I interpret it as meaning he believes that the average developer's baseline calibration for how much is to be assumed is too trusting and people should verify more assumptions than they do-- starting with the most dubious ones of course.