It is through the use of both qualitative stories and quantitative data (surveys and behavioral data) that we are able to uncover needs that people may not even know they have.
Yes! This is why data and design are iteratively better together. Humans (myself included) don’t always have meta-cognitive awareness of what we need. In fact, no amount of reading in behavioral economics, psychology etc. can make me immune to biases in decision-making, or turn me into a truly rational actor. Good design can help us make better decisions, and data inform that successful breed of user-centered design.