Stop designing for "rational" users. Humans are emotional animals. A product that fails emotionally (feels cold, frustrating, or ugly) will fail commercially—even if it is perfectly functional.
Before you download any random file, understand this: Norman’s work fundamentally changed how we build technology. In the past, designers focused solely on usability (Is it easy to use?). Norman argued that emotion is more critical than utility. A beautiful product that is hard to use will be forgiven. An ugly product that works perfectly will be rejected. Design Emocional Donald Norman.pdf