users prefer your site to work the same way as all the other sites

And yet, the last one contradictory reads: "[…]when multiple similar objects are present, the one that differs from the rest is most likely to be remembered." There are no such things as 'rules' in this field. People don't realize how wishy-washy this is and because of that, they throw around some arbitrary rules and then write about it on Medium in a desperate attempt to show authority and demonstrate expertize in their line of work. I could whip out ten other rules that are more applicable and closer to the digital sphere, starting with the notion of 'functionality' instead of some overly complicated and obtuse lingo. In fact, the very first slide has a very weird syntax to it.

And most other sites have dark text on a light background, not light text on a dark background.