You want to learn about what's already in their heads. You want to avoid putting things there.

People don't like silence, so they'll keep talking to fill the void.

The question is, once you have this idea, is this enough? Is it something people would actually switch just to have?

Recording interviews is like magic. a) It stops you from taking notes in the middle and b) you can play that recording for people.

I wish I could tell you the recipe for figuring out who the target user is for your product and who your users should be, but... there isn't a recipe. It comes down to think really hard and use your judgement to figure out who you're really building this for.

Users think they know what they want, but you get the horseless carriage effect where you're getting asked for a faster horse.

The one question you can't ask is, "Is this feature actually good or not?"