If the only people capable of understanding what you are saying are the people that already know it, saying it is quite useless.

Reference material or not.

If I (still) knew it, I wouldn't need reference material. But I agree, if I never knew it, then reference material is... not quite useless, but quite useless to me at the moment.

A reference is a brief reminder and links to primary sources. We don't hate cars because they aren't boats.