Steve Krug’s statement is certainly correct. Yet there are a few useful guiding principles it always helps to have in mind. To learn more about those and some other UX design tips and tricks check his famous book “Don’t Make Me Think!“
Donald A. Norman
An American researcher, professor, and author (The Design of Everyday Things). As Apple’s User Experience Architect (90's), he became the first person to have UX in his job title.