Especially if you try to address their core need but their imagination doesn’t extend quite far enough to see how your effort would help, because they love their ideas.
To the first kind, in contrast, I’m happy to answer any question, no matter how silly it may seem, because I can be confident they’ll trust my judgement, that they’ll learn from the interaction, and that the next one will be even better. Just about the only thing I’m sad about regarding those users is that as they grow they start interacting less because they don’t need it as much, as they are able to help themselves.
Now that I think about it, that seems like a good way to differentiate: The good users delight you and demand of you less and less; the bad users drain you and demand of you more and more.
By and large I’ve gotten better feature requests out of looking at patterns of frequently asked questions and turning them into tasks instead of reacting to negative feedback.