With insight into why people don’t read manuals and why features sell products:
From the Norman essay:
Logic and reason, I have to keep explaining, are wonderful virtues, but they are irrelevant in describing human behavior. Trying to prove a point through intelligent, reasonable argumentation is what I call the “engineer’s fallacy.” (Also, the “economist’s fallacy.") We have to design for the way people really behave, not as engineers or economists would prefer them to behave.
I find myself re-learning this again and again.