Name: Jakob Nielsen, Ph.D.
Job Experience: 30 years of watching people use mainframes, graphical user interfaces, websites, and mobile devices. Since 1998 principal of Nielsen Norman Group. Before then, university professor, Bell Communications Research scientist, and Sun Microsystems Distinguished Engineer.
Most Notable Achievement: Selecting and building a high-functioning team at Nielsen Norman Group, despite having rather poor traditional management skills. It works because the group members all have top-1% IQ and are so achievement-driven that they don't need much traditional management.
Advice: "You are not the target audience."
It is only human for a person to feel that he or she is the center of the universe. After all, we perceive the world as centered around our sensory organs. Everybody views themselves as prime specimens of humanity. In truth we are very different from average people in all the variables that count for assessing usability: we know too much about computers, we know too much about user interfaces, and we definitely know too much about the system we're designing. Anything you think is easy or good might be terrible for the target audience.
That's why we have the discipline of usability engineering: to force ourselves to use systematic methods to see the world through other peoples' eyes instead of designing for our own follies.