It depends on what the subject is. Learning things requires energy, which we don't have an unlimited supply of. If you ask me a question about, say, Hotwheels toys, I'm gonna tell you I don't know the answer, and I do not care nearly enough about Hotwheels to put time and effort into researching anything other than surface-level facts about them. This type of ignorance is fine by me, I'd rather deal with a person who knows they don't know anything about a subject and doesn't care about it than someone who knows little yet cares deeply about it.