You are not the user

Their wordsTesting always works, and even the worst test with the wrong user will show you important things you can do to improve your site.

Their wordsyou're not just working on a static artboard where just mimicking and you're just like a trying to think of all the edge cases, but at the end it's hard to think of those. So you end up just creating the happy path, you know, or just the static path because you're not testing

Their wordsI don't really do user research in a traditional sense because I don't think users know what they want. Your job is to figure it out. So, you should just give people opportunities to tell you things without telling you things.

Their wordsHuman error is blamed for over 90 percent of industrial and automobile accidents. It is the leading cause of aviation accidents, and medical error is reported to be the third-largest cause of death in the entire United States. Horrifying? Yes, but why do we label it “human error”? It is design error.

Their wordsIf you cannot get a group of people for whom your product is designed for to generally agree that your design is good, it’s not good.

Their wordsAnd the trick here is not to act too much on the feedback that the very disappointed people are giving you because they already love your product. Also, not to act at all really on the feedback that the not disappointed people are giving you because they're so far from loving your product that they are essentially a lost cause. but to focus on the segment of the somewhat disappointed people.

Their wordsBut in the end, for something this complicated, it's really hard to design products by focus groups. A lot of times, people don't know what they want until you show it to them.