Why can't I separate what users say from what they need?

You run the interview well. You ask the questions, you get answers, and the answers feel solid because they are concrete — a sentence you can write down and hand to someone else. That is the trap. The sentence feels like the destination because it is easy to hold. But the user is not reporting their need. They are reporting their best guess at a fix, built from whatever they happened to be looking at when you asked. Their words are a symptom. The need is the task they were trying to finish underneath those words — and they rarely say it plainly, because they are not required to know it themselves. That is your job, not theirs. This is not a trick you learn once and keep. It is a habit you either practice on every interview or lose. Choose to practice it on the next one.