Humans are horrible at guessing what others on the road will do. That guy up ahead, following 1.7 car lengths behind the other going 70mph... I have no idea what he will do.
Maybe a bee just stung his genitals, and he's going to careen off the overpass into traffic below. Or he's just another idiot, ready to dart into the other lane at 70mph, with even less distance behind and ahead of him than the 1.7 car lengths.
I can guess the category of actions he will certainly perform (general bad driving, stupid shit, etc.), but I have no psychic powers to know what he will do specifically.
And as for his reactions to driving conditions... for me to simulate those in my head, and come up with something plausible takes more time than it will take him to do it for real by which time it will be too late (and has probably sapped me of the brain power I needed to react myself).
It's a peculiar set of biases, confirmation and other, that let's morons say something like what you quoted.