Affordances, signifiers, mapping, feedback. The vocabulary most design conversations run on comes from this book, which is why reading it late feels like finding the primary source for arguments you have already had.
The central move is to blame the object rather than the person. If people keep pushing a door that pulls, the door is wrong and the sign taped to it is an admission of failure.
Read March 2016. It pairs well with The Inmates Are Running the Asylum, which I had read a decade earlier and which makes the same argument with more hostility.