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

People who are using your product and putting up with all these issues, means that they are not actually the biggest problems.

Who you talk to is just as important as what questions you ask and what you pull away from it.

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

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

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

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.